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Sample records for cox-2 selective inhibitor

  1. Usefulness of selective COX-2 inhibitors as therapeutic agents against canine mammary tumors.

    PubMed

    Saito, Teruyoshi; Tamura, Dai; Asano, Ryuji

    2014-04-01

    Cyclooxygenase-2 (COX-2) is a key enzyme for converting arachidonic acids to prostanoids, which are known to be induced during inflammation and cancer initiation. Previously, it has been reported that COX inhibitors, such as aspirin, reduce the incidence of human colorectal cancer; therefore, it is widely believed that COX-2 is a potential therapeutic and chemoprevention target for several types of human cancer. However, whether selective COX-2 inhibitors have antitumor effects against canine mammary tumor cells remains unclear. In the present study, to elucidate the antitumor effect of selective COX-2 inhibitors against canine mammary tumors, we investigated the antitumor effects of meloxicam, etodolac and celecoxib using COX-2-expressing canine mammary tumor (CF33) cells. We analyzed the effects of selective COX-2 inhibitors on COX-2 protein expression levels in CF33 cells. Celecoxib (100 µM) was found to induce downregulation of COX-2 protein expression. We examined the effect of selective COX-2 inhibitors on CF33 cell proliferation. All the selective COX-2 inhibitors suppressed CF33 cell growth. Specifically, etodolac and celecoxib inhibited cell proliferation via a decrease in S-phase cells and an increase in G0/G1 arrest. We examined the apoptotic effect of selective COX-2 inhibitors on CF33 cells. Our data suggested that etodolac and celecoxib induced apoptosis in CF33 cells. In particular, celecoxib led to apoptosis mediated by the activation of the mitochondrial apoptosis pathway, including the upregulation of BAX expression, downregulation of Bcl-2 expression and activation of caspase-3/7. Furthermore, celecoxib increased the percentages of cells in both early apoptosis and late apoptosis. Our results revealed that celecoxib induced apoptosis and cell cycle arrest in CF33 cells. The data suggested that celecoxib is the most viable candidate as a therapeutic agent for the treatment of canine mammary tumors. Furthermore, our findings provide the first

  2. Selective COX-2 Inhibitors: A Review of Their Structure-Activity Relationships

    PubMed Central

    Zarghi, Afshin; Arfaei, Sara

    2011-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are the competitive inhibitors of cyclooxygenase (COX), the enzyme which mediates the bioconversion of arachidonic acid to inflammatory prostaglandins (PGs). Their use is associated with the side effects such as gastrointestinal and renal toxicity. The therapeutic anti-inflammatory action of NSAIDs is produced by the inhibition of COX-2, while the undesired side effects arise from inhibition of COX-1 activity. Thus, it was though that more selective COX-2 inhibitors would have reduced side effects. Based upon a number of selective COX-2 inhibitors (rofecoxib, celecoxib, valdecoxibetc.) were developed as safer NSAIDs with improved gastric safety profile. However, the recent market removal of some COXIBs such as rofecoxib due to its adverse cardiovascular side effects clearly encourages the researchers to explore and evaluate alternative templates with COX-2 inhibitory activity. Recognition of new avenues for selective COX-2 inhibitors in cancer chemotherapy and neurological diseases such as Parkinson and Alzheimer’s diseases still continues to attract investigations on the development of COX-2 inhibitors. This review highlights the various structural classes of selective COX-2 inhibitors with special emphasis on their structure-activity relationships. PMID:24250402

  3. The 2′-Trifluoromethyl Analogue of Indomethacin Is a Potent and Selective COX-2 Inhibitor

    PubMed Central

    2013-01-01

    Indomethacin is a potent, time-dependent, nonselective inhibitor of the cyclooxygenase enzymes (COX-1 and COX-2). Deletion of the 2′-methyl group of indomethacin produces a weak, reversible COX inhibitor, leading us to explore functionality at that position. Here, we report that substitution of the 2′-methyl group of indomethacin with trifluoromethyl produces CF3–indomethacin, a tight-binding inhibitor with kinetic properties similar to those of indomethacin and unexpected COX-2 selectivity (IC50 mCOX-2 = 267 nM; IC50 oCOX-1 > 100 μM). Studies with site-directed mutants reveal that COX-2 selectivity results from insertion of the CF3 group into a small hydrophobic pocket formed by Ala-527, Val-349, Ser-530, and Leu-531 and projection of the methoxy group toward a side pocket bordered by Val-523. CF3–indomethacin inhibited COX-2 activity in human head and neck squamous cell carcinoma cells and exhibited in vivo anti-inflammatory activity in the carrageenan-induced rat paw edema model with similar potency to that of indomethacin. PMID:23687559

  4. The 2'-Trifluoromethyl Analogue of Indomethacin Is a Potent and Selective COX-2 Inhibitor.

    PubMed

    Blobaum, Anna L; Uddin, Md Jashim; Felts, Andrew S; Crews, Brenda C; Rouzer, Carol A; Marnett, Lawrence J

    2013-05-09

    Indomethacin is a potent, time-dependent, nonselective inhibitor of the cyclooxygenase enzymes (COX-1 and COX-2). Deletion of the 2'-methyl group of indomethacin produces a weak, reversible COX inhibitor, leading us to explore functionality at that position. Here, we report that substitution of the 2'-methyl group of indomethacin with trifluoromethyl produces CF3-indomethacin, a tight-binding inhibitor with kinetic properties similar to those of indomethacin and unexpected COX-2 selectivity (IC50 mCOX-2 = 267 nM; IC50 oCOX-1 > 100 μM). Studies with site-directed mutants reveal that COX-2 selectivity results from insertion of the CF3 group into a small hydrophobic pocket formed by Ala-527, Val-349, Ser-530, and Leu-531 and projection of the methoxy group toward a side pocket bordered by Val-523. CF3-indomethacin inhibited COX-2 activity in human head and neck squamous cell carcinoma cells and exhibited in vivo anti-inflammatory activity in the carrageenan-induced rat paw edema model with similar potency to that of indomethacin.

  5. [Tubulointerstitial nephritis associated with treatment with selective Cox-2 inhibitors, celecoxib and rofecoxib].

    PubMed

    Ortiz, M; Mon, C; Fernández, M J; Sánchez, R; Mampaso, F; Alvarez Ude, F

    2005-01-01

    The nephrotoxic effect of nonselective nonsteroidal anti-inflamatory drugs (NSAIDS) has been widely described. The main benefit of the Cox-2 inhibitors in relation to the NSAIDS is the production of a very similar analgesic effect, but with fewer gastrointestinal side effects. However, their effects on renal function are little known as yet and their long-term safety is still pending definition. The use of selective Cox-2 inhibitors as anti-inflamatory analgesic is becoming more and more common in our environment. We report two cases of tubulointersticial nephritis confirmed by renal biopsy, associated with administration of the two Cox-2 inhibitors currently available on the market, celecoxib and rofecoxib. In both cases, we were talking about elderly women, with deterioration of the general condition and acute renal failure. In the former case, renal biopsy showed an acute tubulo-intersticial nephritis (TIN) so highly "variegated" in its histologic expression. In the second case, was associated with strong indications of chronicity. Treatment with steroid was initiated in both patients and improvement of renal function was observed.

  6. Design and synthesis of benzimidazole analogs endowed with oxadiazole as selective COX-2 inhibitor.

    PubMed

    Rathore, Ankita; Rahman, Mujeeb Ur; Siddiqui, Anees Ahamad; Ali, Abuzer; Shaharyar, Mohammad

    2014-12-01

    New molecules of benzimidazole endowed with oxadiazole were designed and synthesized from 2-(2-((pyrimidin-2-ylthio)methyl)-1H-benzo[d]imidazol-1-yl)acetohydrazide as 1-((5-substituted alkyl/aryl-1,3,4-oxadiazol-2-yl)methyl)-2-((pyrimidin-2-ylthio)methyl)-1H-benzimidazoles (5a-r) with the aim to acquire selective cyclooxygenase (COX-2) inhibitor activity. The synthesized compounds were screened by in vitro cyclooxygenase assays to determine COX-1 and COX-2 inhibitory potency and the results showed that they had good-to-remarkable activity with an IC50 range of 11.6-56.1 µM. The most active compounds were further screened for their in vivo anti-inflammatory activity by using the carrageenan-induced rat paw edema model. In vitro anticancer activities of the hybrid compounds were assessed by the National Cancer Institute (NCI), USA, against 60 human cell lines, and the results showed a good spectrum. Compound 5l exhibited significant COX-2 inhibition with an IC50 value of 8.2 µM and a percent protection of 68.4%. Compound 5b evinced moderate cytotoxicity toward the UO-31 cell line of renal cancer. A docking study was performed using Maestro 9.0, to provide the binding mode into the binding sites of the cyclooxygenase enzyme. Hopefully, in the future, compound 5l could serve as a lead compound for developing new COX-2 inhibitors.

  7. Melatonin, a novel selective ATF-6 inhibitor, induces human hepatoma cell apoptosis through COX-2 downregulation

    PubMed Central

    Bu, Li-Jia; Yu, Han-Qing; Fan, Lu-Lu; Li, Xiao-Qiu; Wang, Fang; Liu, Jia-Tao; Zhong, Fei; Zhang, Cong-Jun; Wei, Wei; Wang, Hua; Sun, Guo-Ping

    2017-01-01

    AIM To clarify the mechanisms involved in the critical endoplasmic reticulum (ER) stress initiating unfolded protein response pathway modified by melatonin. METHODS Hepatoma cells, HepG2, were cultured in vitro. Flow cytometry and TUNEL assay were used to measure HepG2 cell apoptosis. Western blotting and quantitative reverse transcription-polymerase chain reaction methods were used to determine the protein and messenger RNA levels of ER stress and apoptosis related genes’ expression, respectively. Tissue microarray construction from patients was verified by immunohistochemical analysis. RESULTS In the present study, we first identified that melatonin selectively blocked activating transcription factor 6 (ATF-6) and then inhibited cyclooxygenase-2 (COX-2) expression, leading to enhanced liver cancer cell apoptosis under ER stress condition. Dramatically increased CCAAT-enhancer-binding protein homologous protein level, suppressed COX-2 and decreased Bcl-2/Bax ratio by melatonin or ATF-6 siRNA contributed the enhanced HepG2 cell apoptosis under tunicamycin (an ER stress inducer) stimulation. In clinical hepatocellular carcinoma patients, the close relationship between ATF-6 and COX-2 was further confirmed. CONCLUSION These findings indicate that melatonin as a novel selective ATF-6 inhibitor can sensitize human hepatoma cells to ER stress inducing apoptosis. PMID:28246472

  8. The effects of celecoxib, a COX-2 selective inhibitor, on acute inflammation induced in irradiated rats.

    PubMed

    Khayyal, M T; El-Ghazaly, Mona A; El-Hazek, R M; Nada, A S

    2009-10-01

    The potential value of selective and non-selective COX-2 inhibitors in preventing some of the biochemical changes induced by ionizing radiation was studied in rats exposed to carrageenan-induced paw edema and 6-day-old air pouch models. The animals were exposed to different exposure levels of gamma-radiation, namely either to single doses of 2 and 7.5 Gy or a fractionated dose level of 7.5 Gy delivered as 0.5 Gy twice weekly for 7.5 weeks. The inflammatory response produced by carrageenan in irradiated rats was markedly higher than that induced in non-irradiated animals, and depended on the extent of irradiation. Celecoxib, a selective COX-2 inhibitor, in doses of 3, 5, 10, and 15 mg/kg was effective in reducing paw edema in irradiated and non-irradiated rats in a dose-dependent manner as well as diclofenac (3 mg/kg), a non-selective COX inhibitor. Irradiation of animals before the induction of the air pouch by an acute dose of 2 Gy led to a significant increase in leukocytic count, as well as in the level of interleukin-6 (IL-6), interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), LTB(4), PGE(2) (as an index of COX-2 activity), TXB(2) (as an index of COX-1 activity), and the plasma level of MDA. This increase in level of these parameters was more marked than that observed in the non-irradiated animals subjected to the inflammagen. The blood GSH level was not affected by the dose of irradiation used, whereas superoxide dismutase (SOD) activity was suppressed. In many respects, celecoxib (5 mg/kg) was as potent as diclofenac in decreasing the elevated levels of IL-6, IL-1beta, TNF-alpha, LTB(4), PGE(2), but lacked any significant effect on TXB(2) level. Since it is mostly selective for COX-2 with a rare effect on COX-1 enzyme, both drugs at the selected dose levels showed no effect on level of MDA, GSH, and SOD activity.

  9. Biochemical and pharmacological profile of a tetrasubstituted furanone as a highly selective COX-2 inhibitor

    PubMed Central

    Riendeau, D; Percival, M D; Boyce, S; Brideau, C; Charleson, S; Cromlish, W; Ethier, D; Evans, J; Falgueyret, J -P; Ford-Hutchinson, A W; Gordon, R; Greig, G; Gresser, M; Guay, J; Kargman, S; Léger, S; Mancini, J A; O'Neill, G; Ouellet, M; Rodger, I W; Thérien, M; Wang, Z; Webb, J K; Wong, E; Xu, L; Young, R N; Zamboni, R; Prasit, P; Chan, C -C

    1997-01-01

    DFU (5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl)phenyl-2(5H)-furanone) was identified as a novel orally active and highly selective cyclo-oxygenase-2 (COX-2) inhibitor.In CHO cells stably transfected with human COX isozymes, DFU inhibited the arachidonic acid-dependent production of prostaglandin E2 (PGE2) with at least a 1,000 fold selectivity for COX-2 (IC50=41±14 nM) over COX-1 (IC50>50 μM). Indomethacin was a potent inhibitor of both COX-1 (IC50=18±3 nM) and COX-2 (IC50=26±6 nM) under the same assay conditions. The large increase in selectivity of DFU over indomethacin was also observed in COX-1 mediated production of thromboxane B2 (TXB2) by Ca2+ ionophore-challenged human platelets (IC50>50 μM and 4.1±1.7 nM, respectively).DFU caused a time-dependent inhibition of purified recombinant human COX-2 with a Ki value of 140±68 μM for the initial reversible binding to enzyme and a k2 value of 0.11±0.06 s−1 for the first order rate constant for formation of a tightly bound enzyme-inhibitor complex. Comparable values of 62±26 μM and 0.06±0.01 s−1, respectively, were obtained for indomethacin. The enzyme-inhibitor complex was found to have a 1 : 1 stoichiometry and to dissociate only very slowly (t1/2=1–3 h) with recovery of intact inhibitor and active enzyme. The time-dependent inhibition by DFU was decreased by co-incubation with arachidonic acid under non-turnover conditions, consistent with reversible competitive inhibition at the COX active site.Inhibition of purified recombinant human COX-1 by DFU was very weak and observed only at low concentrations of substrate (IC50=63±5 μM at 0.1 μM arachidonic acid). In contrast to COX-2, inhibition was time-independent and rapidly reversible. These data are consistent with a reversible competitive inhibition of COX-1.DFU inhibited lipopolysaccharide (LPS)-induced PGE2 production (COX-2) in a human whole blood assay with a potency (IC50=0.28±0.04 μM) similar

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

    PubMed

    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.

  11. [Side effects of COX-2 selective inhibitors. Critic related with its administration in patients with rheumatoid arthritis and osteoarthritis].

    PubMed

    Carrillo Gutiérrez, Ofmara Y; Pérez Sánchez, Adriana G; Medina Serriteño, Nicolás; Rodríguez Orozco, Alain R

    2007-01-01

    At the end of 2000 the new age of AINEs was introduced, specially the selective inhibitors of the COX-2, whose main function is to block the production of the prostaglandins and the acute tissue inflammation. These inhibitors have analgesic, antithermal and antiinflammatory effects similar to traditional AINEs; they are prescribed specifically to diminish pain and inflammation in patients with rheumatoid arthritis and osteoarthritis. After them introduction, it was reported that they can produce cardiovascular effects, mainly infarcts. This revision exposes the adverse effects that selective inhibitors of the COX-2 produce when elevated doses are administered, during prolonged time, in patients with rheumatoid arthritis and osteoarthritis; in addition, it comments present recommendations for them prescription.

  12. Synthesis and evaluation of benzimidazole derivatives as selective COX-2 inhibitors.

    PubMed

    Rathore, Ankita; Mujeeb-Ur-Rahman; Siddiqui, Anees A; Ali, Abuzer; Yar, Mohammad Shahar

    2015-01-01

    A new series of 1-{(5-substituted-alkyl/aryl-1,3,4-oxadiazol-2-yl)methyl}-2-(piperidin-1-ylmethyl)-1Hbenzimidazoles (5a-5r) was synthesized and screened for their inhibitory activity against COX (1 and 2). In vivo antiinflammatory activity of potent compounds was done by carrageenan-induced rat paw edema model. In vitro anticancer activity of synthesized compounds was also performed at the National Cancer Institute (NCI) against NCI 60 cell lines panel. Out of the 18 compounds screened, 5h, 5i, 5j and 5l were found to be potent COX-2 inhibitors in the range of IC50 0.06-0.81 μM. In vivo anti-inflammatory screening results revealed that the compounds 5h and 5j manifested profound percent protection of 72.8 and 75.0%, respectively. Compound 5f exhibited moderate cytotoxicity with 58.79% growth inhibition against SNB-75 (CNS Cancer) cell lines and moderate activity against COX-2 (IC50 = 8.0 μM).

  13. Selective COX-2 inhibitors: a review of their therapeutic potential and safety in dentistry.

    PubMed

    May, N; Epstein, J; Osborne, B

    2001-10-01

    Anti-inflammatory analgesics are commonly used medications in dental and medical practice. Their uses in dentistry include use as analgesics and as anti-inflammatory agents. In addition, antipyretic action accompanies the medication. The action of these groups of drugs depends on the dose provided. Analgesic and antipyretic effects occur at low dose, whereas analgesic effects occur at high dose. Among the common side effects of this class of medications are gastrointestinal irritation with potential for ulceration, increased tendency for bleeding due to antiplatelet effects, and long-term chronic dosing effects on renal function may occur. Recent developments in the anti-inflammatory group of medications include the introduction of cyclooxygenase-II inhibitors. These agents offer potentially significant advantages because of their relative lack of gastrointestinal irritation. Because of this, it is likely that these medications will be frequently used in the management of dental and medical conditions. Patients will present while on these medications, and these agents may serve as medications for management of dental pain, postsurgical pain, and for anti-inflammatory effects. The current literature indicates that COX-2 inhibitors offer substantial benefits because of their favorable gastrointestinal profiles and because of their lack of effect on platelet function.

  14. Selective Cox-2 inhibitor celecoxib induces epithelial-mesenchymal transition in human lung cancer cells via activating MEK-ERK signaling.

    PubMed

    Wang, Zi-li; Fan, Zhi-qiang; Jiang, Han-dong; Qu, Jie-ming

    2013-03-01

    Increasing evidence has suggested that high expression level of cyclooxygenase-2 (Cox-2) is associated with the malignancies of non-small cell lung cancer (NSCLC), leading to a rationale of applying Cox-2 inhibitors as adjuvant therapy in the treatment of NSCLC. However, the addition of celecoxib, a selective Cox-2 inhibitor, to chemotherapy in clinical trials failed to benefit the survival of NSCLC patients, which urges the investigation to re-evaluate this strategy for NSCLC treatment. In this study, we observed that celecoxib treatment at clinically relevant concentrations induced epithelial-mesenchymal transition (EMT) in NSCLC cells regardless of Cox-2 status, which, however, was not recapitulated using another Cox-2 inhibitor, etodolac. Celecoxib-stimulated EMT in turn promoted cell invasion and rendered cells resistant to chemotherapy. Further mechanistic investigation by disrupting the integrity of signaling pathways using specific inhibitors or RNA interference revealed that celecoxib-induced EMT in NSCLC cells is indispensable of transforming growth factor-β1/Smad signaling. Instead, the activated MEK/ERK/SNAIL1 signaling largely accounted for celecoxib-induced EMT. Taken together, our study reveals the diverse impacts of Cox-2 inhibitors on EMT in NSCLC cells independent of Cox-2 inhibition, where celecoxib treatment leads to metastasis and chemoresistance via EMT induction. These findings reveal the increased risks of cancer metastasis and chemoresistance by applying Cox-2 inhibitors, celecoxib in particular, in clinical trials of NSCLC treatment and urge intensive preclinical assessment before proceeding to clinical application.

  15. Effects of nimesulide, a selective COX-2 inhibitor, on cardiovascular function in 2 rat models of diabetes.

    PubMed

    Leung, Joanne Y T; Pang, Catherine C Y

    2014-07-01

    Cyclooxygenase-2 (COX-2) has been found to be activated in diabetes. We investigated whether nimesulide (selective COX-2 inhibitor) alters cardiovascular responses to adrenaline in 2 rat models of diabetes. Wistar rats (5-week old) were continuously fed a normal or high-fructose diet (60% of caloric intake). At week 2, half of the rats in each diet regimen were given streptozotocin (STZ) (60 mg/kg, intravenously). At week 6, cardiovascular effects of adrenaline (6 and 16 × 10 mol·kg·min, intravenously) were measured in 4 groups of thiobutabarbital-anesthetized rats (control, fructose, STZ, and fructose-streptozotocin [F-STZ]) before and after the injection of nimesulide (3 mg/kg, intravenously). Both the STZ and F-STZ groups exhibited hyperglycemia and significantly (P < 0.05) reduced left ventricular contractility, mean arterial pressure, arterial and venous resistance, and mean circulatory filling pressure (index of venous tone) responses to adrenaline, relative to the control and fructose groups. Nimesulide did not affect responses in the control and fructose groups but increased the venous and, to a less extent, arterial constriction to adrenaline in both the groups of diabetic rats. The cardiac contractile responses, however, were not altered after nimesulide treatment. The results show that nimesulide partially restored arterial and venous constriction to adrenaline in rats with STZ- and F-STZ-induced diabetes.

  16. Targeting KSHV/HHV-8 latency with COX-2 selective inhibitor nimesulide: a potential chemotherapeutic modality for primary effusion lymphoma.

    PubMed

    Paul, Arun George; Sharma-Walia, Neelam; Chandran, Bala

    2011-01-01

    The significance of inflammation in KSHV biology and tumorigenesis prompted us to examine the role of COX-2 in primary effusion lymphoma (PEL), an aggressive AIDS-linked KSHV-associated non-Hodgkin's lymphoma (NHL) using nimesulide, a well-known COX-2 specific NSAID. We demonstrate that (1) nimesulide is efficacious in inducing proliferation arrest in PEL (KSHV+/EBV-; BCBL-1 and BC-3, KSHV+/EBV+; JSC-1), EBV-infected (KSHV-/EBV+; Raji) and non-infected (KSHV-/EBV-; Akata, Loukes, Ramos, BJAB) high malignancy human Burkitt's lymphoma (BL) as well as KSHV-/EBV+ lymphoblastoid (LCL) cell lines; (2) nimesulide is selectively toxic to KSHV infected endothelial cells (TIVE-LTC) compared to TIVE and primary endothelial cells (HMVEC-d); (3) nimesulide reduced KSHV latent gene expression, disrupted p53-LANA-1 protein complexes, and activated the p53/p21 tumor-suppressor pathway; (4) COX-2 inhibition down-regulated cell survival kinases (p-Akt and p-GSK-3β), an angiogenic factor (VEGF-C), PEL defining genes (syndecan-1, aquaporin-3, and vitamin-D3 receptor) and cell cycle proteins such as cyclins E/A and cdc25C; (5) nimesulide induced sustained cell death and G1 arrest in BCBL-1 cells; (6) nimesulide substantially reduced the colony forming capacity of BCBL-1 cells. Overall, our studies provide a comprehensive molecular framework linking COX-2 with PEL pathogenesis and identify the chemotherapeutic potential of nimesulide in treating PEL.

  17. Are COX-2 inhibitors preferable to non-selective non-steroidal anti-inflammatory drugs in patients with risk of cardiovascular events taking low-dose aspirin?

    PubMed

    Strand, Vibeke

    2007-12-22

    Cyclo-oxygenase-2 selective inhibitors and non-selective non-steroidal anti-inflammatory drugs (NSAIDs) are associated with increased risk of acute cardiovascular events. Only aspirin offers primary and secondary cardiovascular prophylaxis, but trials have not answered directly whether low-dose aspirin is cardioprotective with COX-2 inhibitors. A large inception cohort study showed that concomitant use of aspirin reduced risk of cardiovascular events when given with rofecoxib, celecoxib, sulindac, meloxicam, and indometacin but not when given with ibuprofen. In large trials assessing gastrointestinal safety, there were fewer gastrointestinal events in patients using both COX-2 inhibitors and aspirin than in those using non-selective NSAIDs and aspirin; significantly fewer uncomplicated upper gastrointestinal events took place in the MEDAL trial. Analysis of VIGOR and two capsule endoscopy studies showed significantly less distal gastrointestinal blood loss with COX-2 inhibitors than with non-selective NSAIDs. Endoscopy trials showed that low-dose aspirin does not diminish the gastrointestinal benefits of COX-2 inibitors over non-selective NSAIDs. In an elderly epidemiological cohort receiving aspirin, both celecoxib and rofecoxib reduced risk of admission for gastrointestinal events. Comparison of the cardiovascular and gastrointestinal risks is difficult: likelihood and severity of cardiovascular events differ between individuals, agents, and exposure. Mortality associated with gastrointestinal events is less frequent than with cardiovascular events, but asymptomatic ulcers can result in severe complications. Data support the conclusion that COX-2 inhibitors are preferable to non-selective NSAIDs in patients with chronic pain and cardiovascular risk needing low-dose aspirin, but relative risks and benefits should be assessed individually for each patient.

  18. Network Meta-Analysis Comparing Relatively Selective COX-2 Inhibitors Versus Coxibs for the Prevention of NSAID-Induced Gastrointestinal Injury

    PubMed Central

    Yang, Man; Wang, Hong-Tao; Zhao, Miao; Meng, Wen-Bo; Ou, Jin-Qing; He, Jun-Hui; Zou, Bing; Lei, Ping-Guang

    2015-01-01

    Abstract Currently 2 difference classes of cyclooxygenase (COX)-2 inhibitors, coxibs and relatively selective COX-2 inhibitors, are available for patients requiring nonsteroidal anti-inflammatory drug (NSAID) therapy; their gastroprotective effect is hardly directly compared. The aim of this study was to compare the gastroprotective effect of relatively selective COX-2 inhibitors with coxibs. MEDLINE, EMBASE, and the Cochrane Library (from their inception to March 2015) were searched for potential eligible studies. We included randomized controlled trials comparing coxibs (celecoxib, etoricoxib, parecoxib, and lumiracoxib), relatively selective COX-2 inhibitors (nabumetone, meloxicam, and etodolac), and nonselective NSAIDs with a study duration ≥4 weeks. Comparative effectiveness and safety data were pooled by Bayesian network meta-analysis. The primary outcomes were ulcer complications and symptomatic ulcer. Summary effect-size was calculated as risk ratio (RR), together with the 95% confidence interval (CI). This study included 36 trials with a total of 112,351 participants. Network meta-analyses indicated no significant difference between relatively selective COX-2 inhibitors and coxibs regarding ulcer complications (RR, 1.38; 95% CI, 0.47–3.27), symptomatic ulcer (RR, 1.02; 95% CI, 0.09–3.92), and endoscopic ulcer (RR, 1.18; 95% CI, 0.37–2.96). Network meta-analyses adjusting potential influential factors (age, sex, previous ulcer disease, and follow-up time), and sensitivity analyses did not reveal any major change to the main results. Network meta-analyses suggested that relatively selective COX-2 inhibitors and coxibs were associated with comparable incidences of total adverse events (AEs) (RR, 1.09; 95% CI, 0.93–1.31), gastrointestinal AEs (RR, 1.04; 95% CI, 0.87–1.25), total withdrawals (RR, 1.00; 95% CI, 0.74–1.33), and gastrointestinal AE-related withdrawals (RR, 1.02; 95% CI, 0.57–1.74). Relatively selective COX-2 inhibitors appear to be

  19. Enhancement of glioblastoma radioresponse by a selective COX-2 inhibitor celecoxib: Inhibition of tumor angiogenesis with extensive tumor necrosis

    SciTech Connect

    Kang, Khong Bee . E-mail: dmskkb@nccs.com.sg; Wang, Ting Ting; Woon, Chow Thai; Cheah, Elizabeth S.; Moore, Xiao Lei; Zhu Congju; Wong, Meng Cheong

    2007-03-01

    Purpose: Toward improved glioblastoma multiforme treatment, we determined whether celecoxib, a selective cyclooxygenase (COX)-2 inhibitor, could enhance glioblastoma radiosensitivity by inducing tumor necrosis and inhibiting tumor angiogenesis. Methods and Materials: U-87MG cells treated with celecoxib, irradiation, or both were assayed for clonogenic survival and angiogenic factor protein analysis (angiopoietin-1, angiopoietin-2, and vascular endothelial growth factor [VEGF]). In vivo, survival of mice intracranially implanted with U-87MG cells and treated with celecoxib and/or irradiation was monitored. Isolated tumors were assessed for tumor necrosis and tumor microvascular density by von Williebrand's factor (vWF) immunohistochemical staining. Results: Celecoxib (4 and 30 {mu}M; 24, 48, and 72 h) enhanced U-87MG cell radiosensitivity by significantly reducing clonogenic survival of irradiated cells. Angiopoietin-1 and VEGF proteins were decreased, whereas angiopoietin-2 expression increased after 72 h of celecoxib alone and when combined with irradiation. In vivo, median survival of control mice intracranially implanted with U-87MG cells was 18 days. Celecoxib (100 mg/kg/day, 2 weeks) significantly extended median survival of irradiated mice (24 Gy total) from 34 to 41 days, with extensive tumor necrosis [24.5 {+-} 8.6% of tumor region, compared with irradiation alone (2.7 {+-} 1.8%)]. Tumor microvascular density was significantly reduced in combined celecoxib and irradiated tumors (52.5 {+-} 2.9 microvessels per mm{sup 2} tumor region), compared with irradiated tumors alone (65.4 {+-} 4.0 microvessels per mm{sup 2}). Conclusion: Celecoxib significantly enhanced glioblastoma radiosensitivity, reduced clonogenic survival, and prolonged survival of glioblastoma-implanted mice by inhibition of tumor angiogenesis with extensive tumor necr0010os.

  20. Seizure following the Use of the COX-2 Inhibitor Etoricoxib

    PubMed Central

    Arnao, Valentina; Riolo, Marianna; Fierro, Brigida

    2017-01-01

    We describe a case of epileptic seizures occurring after the use of a COX-2 inhibitor. A 61-year-old man was admitted to our department because of a generalized tonic-clonic seizure. EEG showed generalized slowdown of the activity. Neuroimaging and blood samples studies did not evidence alterations, but a careful pharmacological history revealed that the patient had taken the COX-2 inhibitor etoricoxib to treat lumbago few days before the onset of clinical symptoms. No seizures were reported after etoricoxib discontinuation and an EEG resulted to be normal two months after this. Conclusion. Knowing the pharmacological history of a patient is important for understanding the clinical presentation and selecting appropriate treatment. This is, to the best of our knowledge, the first reported case of generalized seizures associated with the use of COX-2 inhibitors. PMID:28210513

  1. Novel 2-phenyl-4,5,6,7-tetrahydro[b]benzothiophene analogues as selective COX-2 inhibitors: Design, synthesis, anti-inflammatory evaluation, and molecular docking studies.

    PubMed

    Khatri, Chetan K; Indalkar, Krishna S; Patil, Chandragouda R; Goyal, Sameer N; Chaturbhuj, Ganesh U

    2017-04-15

    A series of 2-phenyl-4,5,6,7-tetrahydro[b]benzothiophene derivatives were synthesized and evaluated for in vitro COX inhibitory potential. Within the series, compounds 4a, 4j, 4k, and 4q were identified as potential and selective COX-2 inhibitors with COX-2 IC50 in 0.31-1.40µM range; COX-2 selectivity index (SI)=48.8-183.8 range and they showed percent PGE-2 inhibitory activity in the range of 25.4-46.9. Further, compounds 4a, 4j, 4k and 4q displayed potent anti-inflammatory activity with percentage rise in paw volume ranging from 21.1-30.5 at 180min, while celecoxib demonstrated 19.6 percentage rise at the same dose at 180min in carrageenan-induced rat paw edema assay. Cell viability via MTT assay showed no cytotoxicity up to 80µM concentrations. Molecular docking study of potent compounds in the series showed Gscore comparable to celecoxib with similar binding orientation for the COX-2 active site which also corroborates the observed in vitro COX-2 inhibition.

  2. The furoxan system: design of selective nitric oxide (NO) donor inhibitors of COX-2 endowed with anti-aggregatory and vasodilating activities.

    PubMed

    Del Grosso, Erika; Boschi, Donatella; Lazzarato, Loretta; Cena, Clara; Di Stilo, Antonella; Fruttero, Roberta; Moro, Stefano; Gasco, Alberto

    2005-07-01

    Several NO donor 3,4-diphenylfuroxan (= 3,4-diphenyl-1,2,5-oxadiazole 2-oxide) derivatives were synthesized and tested for their COX-inhibiting activities. The products were found to be selective COX-2 inhibitors, similar to the structurally related furazans (3,4-diphenyl-1,2,5-oxadiazole), devoid of the NO release property. This behavior was confirmed by a molecular-docking study. The NO-dependent platelet anti-aggregatory and vasodilating activities of the new furoxans 5-7 were studied in vitro. These properties can be modulated by inserting an appropriate spacer between the 4-phenyl group and the furoxan ring, giving rise to new, selective COX-2 furoxan derivatives endowed with anti-aggregatory and vasodilating activities, and with potentially reduced cardiotoxicities.

  3. NS-398, a selective COX-2 inhibitor, inhibits proliferation of IL-1{beta}-stimulated vascular smooth muscle cells by induction of {eta}{omicron}-1

    SciTech Connect

    Choi, Hyoung Chul; Kim, Hee Sun; Lee, Kwang Youn; Chang, Ki Churl Kang, Young Jin

    2008-11-28

    We investigated whether NS-398, a selective inhibitor of COX-2, induces HO-1 in IL-1{beta}-stimulated vascular smooth muscle cells (VSMC). NS-398 reduced the production of PGE{sub 2} without modulation of expression of COX-2 in IL-1{beta}-stimulated VSMC. NS-398 increased HO-1 mRNA and protein in a dose-dependent manner, but inhibited proliferation of IL-1{beta}-stimulated VSMC. Furthermore, SnPPIX, a HO-1 inhibitor, reversed the effects of NS-398 on PGE{sub 2} production, suggesting that COX-2 activity can be affected by HO-1. Hemin, a HO-1 inducer, also reduced the production of PGE{sub 2} and proliferation of IL-1{beta}-stimulated VSMC. CORM-2, a CO-releasing molecule, but not bilirubin inhibited proliferation of IL-1{beta}-stimulated VSMC. NS-398 inhibited proliferation of IL-1{beta}-stimulated VSMC in a HbO{sub 2}-sensitive manner. In conclusion, NS-398 inhibits proliferation of IL-1{beta}-stimulated VSMC by HO-1-derived CO. Thus, NS-398 may facilitate the healing process of vessels in vascular inflammatory disorders such as atherosclerosis.

  4. Synthesis and evaluation of fluorobenzoylated di- and tripeptides as inhibitors of cyclooxygenase-2 (COX-2).

    PubMed

    Sharma, Sai Kiran; Al-Hourani, Baker Jawabrah; Wuest, Melinda; Mane, Jonathan Y; Tuszynski, Jack; Baracos, Vickie; Suresh, Mavanur; Wuest, Frank

    2012-04-01

    A series of fluorobenzoylated di- and tripeptides as potential leads for the development of molecular probes for imaging of COX-2 expression was prepared according to standard Fmoc-based solid-phase peptide synthesis. All peptides were assessed for their COX-2 inhibitory potency and selectivity profile in a fluorescence-based COX binding assay. Within the series of 15 peptides tested, cysteine-containing peptides numbered 7, 8, 11 and 12, respectively, were the most potent COX-2 inhibitors possessing IC(50) values ranging from 5 to 85 μM. Fluorobenzoylated tripeptides 7 and 8 displayed some COX-2 selectivity (COX-2 selectivity index 2.1 and 1.6), whereas fluorobenzoylated dipeptides 11 and 12 were shown not to be COX-2 selective. Fluorbenzoylated tripeptide FB-Phe-Cys-Ser-OH was further used in molecular modeling docking studies to determine the binding mode within the active site of the COX-2 enzyme.

  5. QSAR and classification models of a novel series of COX-2 selective inhibitors: 1,5-diarylimidazoles based on support vector machines.

    PubMed

    Liu, H X; Zhang, R S; Yao, X J; Liu, M C; Hu, Z D; Fan, B T

    2004-06-01

    The support vector machine, which is a novel algorithm from the machine learning community, was used to develop quantitation and classification models which can be used as a potential screening mechanism for a novel series of COX-2 selective inhibitors. Each compound was represented by calculated structural descriptors that encode constitutional, topological, geometrical, electrostatic, and quantum-chemical features. The heuristic method was then used to search the descriptor space and select the descriptors responsible for activity. Quantitative modelling results in a nonlinear, seven-descriptor model based on SVMs with root mean-square errors of 0.107 and 0.136 for training and prediction sets, respectively. The best classification results are found using SVMs: the accuracy for training and test sets is 91.2% and 88.2%, respectively. This paper proposes a new and effective method for drug design and screening.

  6. Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization

    SciTech Connect

    Meng, Zhen; Gan, Ye-Hua

    2015-05-01

    Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation. - Highlights: • COX-2 inhibitor, celecoxib, could enhance radiosensitization. • Radiation induced PTEN inactivation (phosphorylation) and AKT activation. • COX-2 inhibitor induced PTEN expression and activation, and inactivated AKT. • COX-2 inhibitor enhanced radiosensitization through activating PTEN.

  7. Design, Synthesis and Biological Evaluation of4-(Imidazolylmethyl)-2-(4-methylsulfonyl phenyl)-Quinoline Derivatives as Selective COX-2 Inhibitors and In-vitro Anti-breast Cancer Agents

    PubMed Central

    Ghodsi, Razieh; Azizi, Ebrahim; Zarghi, Afshin

    2016-01-01

    A new group of 4-(Imidazolylmethyl)quinoline derivatives possessing a methylsulfonyl COX-2 pharmacophore at the para position of the C-2 phenyl ring were designed and synthesized as selective COX-2 inhibitors and in-vitroanti breast cancer agents. In-vitro COX-1 and COX-2 inhibition studies showed that all the compounds were potent and selective inhibitors of the COX-2 isozyme with IC50 values in the potent range 0.063-0.090 µM, and COX-2 selectivity indexes in the 179.9 to 547.6 range. Molecular modeling studies indicated that the methylsulfonyl substituent can be inserted into the secondary pocket of COX-2 active site for interactions with Arg513. Cytotoxicity of quinolines 9a-e against human breast cancer MCF-7 and T47D cell lines were also evaluated. All the compounds 9a-e were more cytotoxic against MCF-7 cells in comparison with those of T47D which express aromatase mRNA less than MCF-7 cells.The data showed that the increase of lipophilic properties of substituents on the C-7 and C-8 quinoline ring increased their cytotoxicity on MCF-7cells andCOX-2 inhibitory activity. Among the quinolines 9a-e, 4-((1H-Imidazol-1-yl)methyl) 7,8,9,10-tetrahydro-2-(4-methylsulfonylphenyl)-benzo[h]quinoline (9d)was identified as the most potent andselective COX-2inhibitor as well as the most cytotoxic agent against MCF-7 cells. PMID:27610157

  8. Multifocal Fixed Drug Eruption with COX-2 Inhibitor-Celecoxib

    PubMed Central

    Chugh, Shikha; Sarkar, Rashmi; Garg, Vijay K; Singh, Avninder; Keisham, Chitralekha

    2013-01-01

    Cyclooxygenase-2 (COX-2) inhibitors are rapidly becoming the first choice nonsteroidal anti-inflammatory drugs (NSAIDs) for various rheumatological and other painful conditions. However, they might not be as safe or free of side effects as they are considered to be. These COX-2inhibitors may cause a variety of dermatological and systemic side effects of which we should be aware to avoid their indiscriminate use. We hereby report a case of multifocal fixed drug eruption (FDE) with celecoxib which has not yet been reported in Indian settings. PMID:23716804

  9. Multifocal Fixed Drug Eruption with COX-2 Inhibitor-Celecoxib.

    PubMed

    Chugh, Shikha; Sarkar, Rashmi; Garg, Vijay K; Singh, Avninder; Keisham, Chitralekha

    2013-03-01

    Cyclooxygenase-2 (COX-2) inhibitors are rapidly becoming the first choice nonsteroidal anti-inflammatory drugs (NSAIDs) for various rheumatological and other painful conditions. However, they might not be as safe or free of side effects as they are considered to be. These COX-2inhibitors may cause a variety of dermatological and systemic side effects of which we should be aware to avoid their indiscriminate use. We hereby report a case of multifocal fixed drug eruption (FDE) with celecoxib which has not yet been reported in Indian settings.

  10. QSAR analyses of conformationally restricted 1,5-diaryl pyrazoles as selective COX-2 inhibitors: application of connection table representation of ligands.

    PubMed

    Prasanna, S; Manivannan, E; Chaturvedi, S C

    2005-04-15

    As a part of our continuing efforts in discerning the structural and physicochemical requirements for selective COX-2 over COX-1 inhibition among the fused pyrazole ring systems, herein we report the QSAR analyses of the title compounds. The conformational flexibility of the title compounds was examined using a simple connection table representation. The conformational investigation was aided by calculating a connection table parameter called fraction of rotable bonds, b_rotR encompassing the number of rotable bonds and b_count, the number of bonds including implicit hydrogens of each ligand. The hydrophobic and steric correlation of the title compounds towards selective COX-2 inhibition was reported previously in one of our recent publications. In this communication, we attempt to calculate Wang-Ford charges of the non-hydrogen common atoms of AM1 optimized geometries of the title compounds. Owing to the partial conformational flexibility of title compounds, conformationally restricted and unrestricted descriptors were calculated from MOE. Correlation analysis of these 2D, 3D and Wang-Ford charges was accomplished by linear regression analysis. 2D molecular descriptor b_single, 3D molecular descriptors glob, std_dim3 showed significant contribution towards COX-2 inhibitory activity. Balaban J, a connectivity topological index showed a negative and positive contribution towards COX-1 and selective COX-2 over COX-1 inhibition, respectively. Wang-Ford charges calculated on C(7) showed a significant contribution towards COX-1 inhibitory activity whereas charges calculated on C(8) were crucial in governing the selectivity of COX-2 over COX-1 inhibition among these congeners.

  11. Design and synthesis of novel 2-phenyl-5-(1,3-diphenyl-1H-pyrazol-4-yl)-1,3,4-oxadiazoles as selective COX-2 inhibitors with potent anti-inflammatory activity.

    PubMed

    Bansal, Sumit; Bala, Manju; Suthar, Sharad Kumar; Choudhary, Shivani; Bhattacharya, Shoumyo; Bhardwaj, Varun; Singla, Sumit; Joseph, Alex

    2014-06-10

    A novel series of 2-phenyl-5-(1,3-diphenyl-1H-pyrazol-4-yl)-1,3,4-oxadiazoles were designed and synthesized for selective COX-2 inhibition with potent anti-inflammatory activity. Among the compounds tested, 9g (2-(3-(4-nitrophenyl)-1-phenyl-1H-pyrazol-4-yl)-5-phenyl-1,3,4-oxadiazole) was found to be the most potent inhibitor of COX-2 with IC50 of 0.31 μM showing promising degree of anti-inflammatory activity in the carrageenan-induced rat paw edema model with ED50 of 74.3 mg/kg. The lead compound 9g further showed suppression of acetic acid-induced writhes comparable to that of aspirin and gastro-sparing profile superior to the aspirin. Molecular docking analysis displayed higher binding affinity of ligands towards COX-2 than COX-1.

  12. Effect of COX-2 inhibitor after TNBS-induced colitis in Wistar rats.

    PubMed

    Paiotti, Ana Paula Ribeiro; Miszputen, Sender Jankiel; Oshima, Celina Tizuko Fujiyama; de Oliveira Costa, Henrique; Ribeiro, Daniel Araki; Franco, Marcello

    2009-08-01

    Inflammatory bowel disease (IBD) is a common chronic gastrointestinal disorder characterized by alternating periods of remission and active intestinal inflammation. Some studies suggest that antiinflammatory drugs are a promising alternative for treatment of the disease. Thus, this study aimed to evaluate the effect of lumiracoxib, a selective-cyclooxygenase-2 (COX-2) inhibitor, on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis. Wistar rats (n = 25) were randomized into four groups, as follows: Group (1) Sham group: sham induced-colitis rats; Group (2) TNBS group: nontreated induced-colitis rats; Group (3) Lumiracoxib control group; and Group (4) Lumiracoxib-treated induced-colitis rats. Our results showed that rats from groups 2 and 4 presented similar histopathological damage and macroscopic injury in the distal colon as depicted by significant statistically differences (P < 0.01; P < 0.05) compared to the other two groups. Weak expression of COX-2 mRNA was detected in normal colon cells, while higher levels of COX-2 mRNA were detected in group 2 and group 4. Therapy with lumiracoxib reduced COX-2 expression by 20-30%, but it was still higher and statistically significant compared to data obtained from the lumiracoxib control group. Treatment with the selective COX-2 inhibitor lumiracoxib did not reduce inflammation-associated colonic injury in TNBS-induced experimental colitis. Thus, the use of COX-2 inhibitors for treating IBD should be considered with caution and warrants further experimental investigation to elucidate their applicability.

  13. Efficacy and Safety of COX-2 Inhibitors in the Clinical Management of Arthritis: Mini Review

    PubMed Central

    Mathew, Sam T.; Devi S, Gayathri; Prasanth, V. V.; Vinod, B.

    2011-01-01

    In the clinical management of arthritis, the choice of nonsteroidal anti inflammatory drug (NSAID) remains confusing and controversial. A common practice on the choice of NSAID in clinical management of arthritis is the risk benefit ratio. The main objective of this review is to addresses the main arguments for the pharmacological and clinical use of COX-2 inhibitors in relation to nonselective NSAIDs for the clinical management of arthritis. This review concluded that, both NSAIDs and COX-2 inhibitors are equally effective and are associated with increased risk of GI, renal, and CV, adverse effects. Complete understanding of the patient's comorbid conditions and concomitant medications, coupled with precise monitoring during the treatment, may help to decrease the threat of adverse effects induced by nonselective NSAIDs and selective COX-2 inhibitors. PMID:22084715

  14. Diclofenac, a selective COX-2 inhibitor, inhibits DMH-induced colon tumorigenesis through suppression of MCP-1, MIP-1α and VEGF.

    PubMed

    Kaur, Jasmeet; Sanyal, S N

    2011-09-01

    Angiogenesis is a physiological process involving growth of new blood vessels from pre-existing ones; however, it also plays a critical role in tumor progression. It favors the transition from hyperplasia to neoplasia, that is, from a state of cellular multiplication to uncontrolled proliferation. Therefore targeting angiogenesis will be profitable as a mechanism to inhibit tumor's lifeline. Further, it is important to understand the cross-communication between vascular endothelial growth factor (VEGF)-master switch in angiogenesis and other molecules in the neoplastic and pro-inflammatory milieu. We studied the role of two important chemokines [monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-lα] alongwith VEGF and matrix metalloproteinases (MMPs) in non-steroidal anti-inflammatory drugs (NSAIDs)-induced chemopreventive effect in experimental colon cancer in rat. 1,2-Dimethylhydrazine (DMH, 30 mg/kg body weight, subcutaneously (s.c.) once-a-week) for 18 wk was used as pro-carcinogen and diclofenac (8 mg/kg body weight, orally daily) as the preferential cyclooxygenase-2 (COX-2) inhibitor. Expression of COX-2 and VEGF was found to be significantly elevated in the DMH-treated group as compared to the control, which was lowered notably by Diclofenac co-administration with DMH. Gelatin zymography showed prominent MMP-9 activity in the DMH-treated rats, while the activity was nearly absent in all the other groups. Expression of MCP-1 was found to be markedly increased whereas MIP-1α expression was found to be decreased in colonic mucosa from DMH-treated rats, which was reversed in the DMH + Diclofenac group. Our results indicate potential role of chemokines alongwith VEGF in angiogenesis in DMH-induced cancer and its chemoprevention with diclofenac.

  15. Structure-based parallel medicinal chemistry approach to improve metabolic stability of benzopyran COX-2 inhibitors.

    PubMed

    Xing, Li; Hamper, Bruce C; Fletcher, Theresa R; Wendling, Jay M; Carter, Jeffery; Gierse, James K; Liao, Subo

    2011-02-01

    Combination of the structure-based design and solid-phase parallel synthesis provided an integrated approach to rapidly develop the structure-activity relationship of benzopyran COX-2 inhibitors. Binding free energies predicted by free energy perturbation theory yielded good agreement with experimental results. New potent and selective lead compounds with improved metabolic properties were identified.

  16. COX-2 inhibitors: a story of greed, deception and death.

    PubMed

    Halpern, Georges M

    2005-01-01

    In 1999, drug manufacturers introduced a class of NSAIDs called COX-2 inhibitors or coxibs. The drugs were avidly promoted directly to the consumers and became bestsellers from the start. Arthritis sufferers were eager to take medications that eased joint pain with less risk of causing gastrointestinal pain, bleeding and other side-effects. In the year after their introduction, doctors wrote over 100 million prescriptions for celecoxib (Celebrex) and rofecoxib (Vioxx). Celebrex is the sixth best-selling drug, with sales of more than US$ 4 billion since its debut in 1999. Vioxx had sales of US$ 2.6 billion in 2001. However, the coxibs increase the risk of heart attacks and strokes, and their price, in the USA, is obscene. The manufacturers faced a possibly complicit, toothless and bloodless FDA, and used every maneuvering to fleece the patients. We must now reflect on attitudes that we thought only belong to the tobacco industry. Fortunately, safe and active alternatives exist.

  17. [Specific inhibitors of cyclooxygenase-2 (COX-2): current knowledge and perspectives].

    PubMed

    Rioda, W T; Nervetti, A

    2001-01-01

    The Authors summarize the current knowledge on a new class of nonsteroidal anti-inflammatory drugs (NSAIDs), the coxib (celecoxib and rofecoxib), in the treatment of rheumatic diseases. Celecoxib and rofecoxib are selective cyclooxygenase-2 (COX-2) inhibitors which possess the same anti-inflammatory and analgesic activities, but a better gastric tolerability compared to the non-selective COX-1 and COX-2 inhibitors. The Authors also report other possible therapeutic effects of these NSADIs as evidenced by the more recent data of the literature. Celecoxib seems to reduce the incidence of new polyps in patients with familial adenomatous polyposis. It has been suggested the use of celecoxib as a protective drug against the development of colorectal cancer. Other (neoplastic) or pre-neoplastic conditions, such as bladder dysplasia, Barret esophagus, attinic keratosis and Alzheimer's disease seem to have benefit from this class of drugs.

  18. Nimesulide, a selective COX-2 inhibitor, acts synergistically with ionizing radiation against A549 human lung cancer cells through the activation of caspase-8 and caspase-3.

    PubMed

    Kim, Byeong Mo; Won, Juyoon; Maeng, Kyung Ah; Han, Young Soo; Yun, Yeon-Sook; Hong, Sung Hee

    2009-05-01

    Several lines of evidence suggest that non-steroidal anti-inflammatory drugs (NSAIDs) have a radiosensitizing effect on cancer cells in vitro and in vivo, but little is known about the underlying cellular mechanism. In this study, we found that the treatment with the NSAID nimesulide significantly increased the sensitivity of A549 human non-small cell lung cancer cells to radiotherapy. The combined nimesulide-radiation treatment increased apoptosis, induced the cleavage of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP), activated caspase-8, and induced cleavage of Bid. A pan-caspase inhibitor, z-VAD-fmk, suppressed this increase in apoptosis and also suppressed the cleavage of caspase-8, caspase-3, and PARP, suggesting a caspase-dependent mechanism. In addition, z-IETD-fmk, a selective caspase-8 inhibitor, suppressed the nimesulide- and radiation-induced cleavage activation of caspase-9, caspase-3, caspase-8, and Bid, and suppressed the concomitant apoptosis, indicating that the nimesulide-induced increase in radiosensitivity was initiated by caspase-8. However, the caspase-3 inhibitor z-DEVD-fmk failed to suppress activation of the caspase-8/Bid pathway, indicating that caspase-3 activation occurred downstream of caspase-8 activation in our experiments. Marked antitumor effects, which were evaluated by measuring protracted tumor regression, were observed when nude mice were treated with a combination of nimesulide at a clinically achievable dose (0.5 mg/kg) and radiation therapy. Our results, demonstrating the radiosensitivity-increasing and tumor growth-inhibiting effects of nimesulide, suggest that nimesulide may be suitable as an adjuvant to enhance the efficacy and selectivity of radiotherapy.

  19. Novel COX-2 Inhibitor for Breast Cancer Therapy

    DTIC Science & Technology

    2005-07-01

    exothermic, chloroacetic acid (18.14 g, 192 mmol) was added portion wise, and the reaction mixture was re- fluxed for 5 h. This mixture was then poured into...arachadonic acid to prostaglandins (PGs) (Vane and Botting, 1998). Recent studies have shown that high levels of COX-2 are expressed in a large percentage...7.5 0 µM 3 µM 5 µM 8 µM Celebrex A Arachidonic acid (µM) Figure 9: Effect of substrate concentrations on the inactivation of COX-2 by Celebrex (A

  20. COX-2 inhibitors: a novel strategy in the management of breast cancer.

    PubMed

    Regulski, Miłosz; Regulska, Katarzyna; Prukała, Wiesław; Piotrowska, Hanna; Stanisz, Beata; Murias, Marek

    2016-04-01

    Cyclooxygenase-2 (COX-2) inhibitors are common anti-inflammatory drugs with pleiotropic, endogenous actions that could be useful in the management of breast cancer. Here, we provide a complete understanding of the biochemistry of COX-2 and discuss the various molecular mechanisms behind its increased expression in breast cancer. We also analyze the possible mechanisms responsible for the anticancer effect of COX-2 inhibitors and provide an overview of the available preclinical and clinical data on the use of COX-2 inhibitors in breast cancer. Finally, we describe a mathematical model of the relation between the structure and biological potency of promising new COX-2 inhibitors (trans-stilbenes) using a 2D quantitative structure-activity relationship (QSAR) technique.

  1. Targeting COX-2 expression by natural compounds: a promising alternative strategy to synthetic COX-2 inhibitors for cancer chemoprevention and therapy.

    PubMed

    Cerella, Claudia; Sobolewski, Cyril; Dicato, Mario; Diederich, Marc

    2010-12-15

    Cyclooxygenase (COX)-2 is a pro-inflammatory immediate early response protein, chronically up-regulated in many pathological conditions. In autoimmune diseases, it is responsible for degenerative effects whereas in cancer, it correlates with poor prognosis. A constitutive expression of COX-2 is triggered since the earliest steps of carcinogenesis. Consequently, strategies aimed at inhibiting COX-2 enzymatic activity have been clinically applied for the treatment of autoimmune disorders; in addition, the same approaches are currently investigated for anti-cancer purposes. However, COX-2 protein inhibitors (i.e., NSAIDs and COXIBs) are not amenable to prolonged administration since they may cause severe side effects, and efforts are underway to identify alternative approaches for chemoprevention/therapy. COX-2 expression is a multi-step process, highly regulated at transcriptional and post-transcriptional levels. Defects in the modulation of one or both of these steps may be found in pathological conditions. Targeting COX-2 expression may therefore represent a promising strategy, by which the same preventive and therapeutic benefits may be gained while avoiding the severe side effects of COX-2 enzymatic inhibition. Naturally occurring compounds derived from plants/organisms represent a huge source of biologically active molecules, that remains largely unexplored. Derived from plants/organisms used in traditional forms of medicine or as dietary supplements, these compounds have been experimentally investigated for their anti-inflammatory and anti-cancer potential. In this review, we will analyze how natural compounds may modulate the multistep regulation of COX-2 gene expression and discuss their potential as a new generation of COX-2 targeting agents alternative to the synthetic COX-2 inhibitors.

  2. Antiinflammatory 2-benzyl-4-sulfonyl-4H-isoquinoline-1,3-diones: novel inhibitors of COX-2.

    PubMed

    Lazer, E S; Sorcek, R; Cywin, C L; Thome, D; Possanza, G J; Graham, A G; Churchill, L

    1998-05-19

    A series of 2-benzyl-4-sulfonyl-4H-isoquinoline-1,3-diones was prepared. Members of this series are potent and selective inhibitors of cyclooxygenase-2 (COX-2) in both microsomal and cellular assays. Two representatives demonstrated activity in the carrageenan-induced paw edema model in rats upon oral administration.

  3. [Effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of HL-60 cells and its mechanism].

    PubMed

    Xie, Xia; Li, Jie; Wang, Rui-Cang; Geng, Rui-Li; Wang, Su-Yun; Wang, Chao; Zhao, Xiao-Yun; Hao, Hong-Ling

    2014-06-01

    This study was aimed to investigate the effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of human acute myeloid leukemia cell line HL-60 and its mechanism. HL-60 cells were cultured with different concentrations of celecoxib for 24 h. Cell proliferation was analyzed by CCK-8 assay, cell apoptosis and cell cycle distribution were detected by flow cytometry. Cyclin D1, cyclin E1 and COX-2 mRNA expressions were determined by RT-PCR. The results showed that after the HL-60 cells were treated with different concentrations of celecoxib for 24 h, the cell growth was significantly inhibited in a dose-dependent manner(r = 0.955), IC50 was 63.037 µmol/L of celecoxib. Celecoxib could effectively induce apoptosis in HL-60 cells also in dose-dependent manner(r = 0.988), blocked the HL-60 cells in the G0/G1 phase. The expression of cyclin D1, cyclin E1 and COX-2 mRNA were downregulated. It is concluded that celecoxib can inhibit the proliferation of HL-60 cells in dose-dependent manner, celecoxib causes cell G0/G1 arrest and induces cell apoptosis possibly through down-regulation of the cyclin D1 and cyclin E1 expression, and down-regulation of COX-2 expression respectively.

  4. COX-2 chronology

    PubMed Central

    Hawkey, C J

    2005-01-01

    The role of selective cyclooxygenase (COX)-2 inhibitors in medical practice has become controversial since evidence emerged that their use is associated with an increased risk of myocardial infarction. Selective COX-2 inhibitors were seen as successor to non-selective non-steroidal anti-inflammatory drugs, in turn successors to aspirin. The importance of pain relief means that such drugs have always attracted attention. The fact that they work through inhibition of cyclooxygenase, are widespread, and have multiple effects also means that adverse effects that were unanticipated (even though predictable) have always emerged. In this paper I therefore present an historical perspective so that the lessons of the past may be applied to the present. PMID:16227351

  5. Comparison of nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 (COX-2) inhibitors use in Australia and Nova Scotia (Canada)

    PubMed Central

    Barozzi, Nadia; Sketris, Ingrid; Cooke, Charmaine; Tett, Susan

    2009-01-01

    AIMS Cyclooxygenase-2 (COX-2) inhibitors were marketed aggressively and their rapid uptake caused safety concerns and budgetary challenges in Canada and Australia. The objectives of this study were to compare and contrast COX-2 inhibitors and nonselective nonsteroidal anti-inflammatory drug (ns-NSAID) use in Nova Scotia (Canada) and Australia and to identify lessons learned from the two jurisdictions. METHODS Ns-NSAID and COX-2 inhibitor Australian prescription data (concession beneficiaries) were downloaded from the Medicare Australia website (2001–2006). Similar Pharmacare data were obtained for Nova Scotia (seniors and those receiving Community services). Defined daily doses per 1000 beneficiaries day−1 were calculated. COX-2 inhibitors/all NSAIDs ratios were calculated for Australia and Nova Scotia. Ns-NSAIDs were divided into low, moderate and high risk for gastrointestinal side-effects and the proportions of use in each group were determined. Which drugs accounted for 90% of use was also calculated. RESULTS Overall NSAID use was different in Australia and Nova Scotia. However, ns-NSAID use was similar. COX-2 inhibitor dispensing was higher in Australia. The percentage of COX-2 inhibitor prescriptions over the total NSAID use was different in the two countries. High-risk NSAID use was much higher in Australia. Low-risk NSAID prescribing increased in Nova Scotia over time. The low-risk/high-risk ratio was constant throughout over the period in Australia and increased in Nova Scotia. CONCLUSIONS There are significant differences in Australia and Nova Scotia in use of NSAIDs, mainly due to COX-2 prescribing. Nova Scotia has a higher proportion of low-risk NSAID use. Interventions to provide physicians with information on relative benefits and risks of prescribing specific NSAIDs are needed, including determining their impact. PMID:19660008

  6. Diaryl-Substituted (Dihydro)pyrrolo[3,2,1-hi]indoles, a Class of Potent COX-2 Inhibitors with Tricyclic Core Structure.

    PubMed

    Laube, Markus; Gassner, Cemena; Sharma, Sai Kiran; Günther, Robert; Pigorsch, Arne; König, Jonas; Köckerling, Martin; Wuest, Frank; Pietzsch, Jens; Kniess, Torsten

    2015-06-05

    A new compound class of diaryl-substituted heterocycles with tricyclic dihydropyrrolo[3,2,1-hi]indole and pyrrolo[3,2,1-hi]indole core structures has been designed and was synthesized by a modular sequence of Friedel-Crafts acylation, amide formation, and McMurry cyclization. This synthesis route represents a novel and versatile access toward dihydropyrrolo[3,2,1-hi]indoles and is characterized by good chemical yields and high modularity. From a set of 19 derivatives, 11 candidates were selected for determination of their COX inhibition potency and were found to be selective inhibitors with high affinity to COX-2 (IC50 ranging from 20-2500 nM and negligible inhibition of COX-1). The binding mode of the novel inhibitors in the active side of COX-2 was calculated in silico using the protein-ligand docking program GOLD by application of the molecular structures of two compounds derived from X-ray crystallography. Two novel compounds with high affinity to COX-2 (6k = 70 nM, 8e = 60 nM) have a fluoro substituent, making them promising candidates for the development of (18)F-radiolabeled COX-2 inhibitors for imaging purposes with positron emission tomography (PET).

  7. Pharmacophore Elucidation and Molecular Docking Studies on 5-Phenyl-1-(3-pyridyl)-1H-1,2,4-triazole-3-carboxylic Acid Derivatives as COX-2 Inhibitors

    PubMed Central

    Lindner, Marc; Sippl, Wolfgang; Radwan, Awwad A.

    2010-01-01

    A set of 5-phenyl-1-(3-pyridyl)-1H-1,2,4-triazole-3-carboxylic acid derivatives (16–32) showing anti-inflammatory activity was analyzed using a three-dimensional qualitative structure-selectivity relationship (3D QSSR) method. The CatalystHipHop approach was used to generate a pharmacophore model for cyclooxygenase-2 (COX-2) inhibitors based on a training set of 15 active inhibitors (1–15). The degree of fitting of the test set compounds (16–32) to the generated hypothetical model revealed a qualitative measure of the more or less selective COX-2 inhibition of these compounds. The results indicate that most derivatives (16, 18, 20–25, and 30–32) are able to effectively satisfy the proposed pharmacophore geometry using energy accessible conformers (Econf < 20 kcal/mol). In addition, the triazole derivatives (16–32) were docked into COX-1 and COX-2 X-ray structures, using the program GOLD. Based on the docking results it is suggested that several of these novel triazole derivatives are active COX inhibitors with a significant preference for COX-2. In principle, this work presents an interesting, comprehensive approach to theoretically predict the mode of action of compounds that showed anti-inflammatory activity in an in vivo model. PMID:21179343

  8. Insights from the docking analysis of biologically active compounds from plant Litsea Genus as potential COX-2 inhibitors

    PubMed Central

    Gogoi, Dhrubajyoti; Bezbaruah, Rajib Lochan; Bordoloi, Manabjyoti; Sarmah, Rajeev; Bora, Tarun Chandra

    2012-01-01

    Litsea spp of Laural family are traditionally used as herbal medicine for treating inflammation including gastroenterologia, oedema and rheumatic arthritis. Therefore, it is of interest to investigate and understand the molecular principles for such actions. Here, we have illustrated the binding of thirteen Litsea derived biologically active compounds against the inflammation associated target COX (cyclo-oxygenase) -2 enzymes. We compared the binding information of these compounds with a selected number of already known COX-2 inhibitors. The comparison reflected that some of these compounds such as linderol, catechin, 6'-hydroxy-2',3',4' - trimethoxy-chalcone and litseaone have better or equivalent binding features compared to already known inhibitory compounds namely celecoxib, acetylsalicylic acid, rofecoxib. Therefore, all these small compounds reported from plant Litsea spp were found to possess potential medicinal values with anti-inflammatory properties. PMID:23139590

  9. Insights from the docking analysis of biologically active compounds from plant Litsea Genus as potential COX-2 inhibitors.

    PubMed

    Gogoi, Dhrubajyoti; Bezbaruah, Rajib Lochan; Bordoloi, Manabjyoti; Sarmah, Rajeev; Bora, Tarun Chandra

    2012-01-01

    Litsea spp of Laural family are traditionally used as herbal medicine for treating inflammation including gastroenterologia, oedema and rheumatic arthritis. Therefore, it is of interest to investigate and understand the molecular principles for such actions. Here, we have illustrated the binding of thirteen Litsea derived biologically active compounds against the inflammation associated target COX (cyclo-oxygenase) -2 enzymes. We compared the binding information of these compounds with a selected number of already known COX-2 inhibitors. The comparison reflected that some of these compounds such as linderol, catechin, 6'-hydroxy-2',3',4' - trimethoxy-chalcone and litseaone have better or equivalent binding features compared to already known inhibitory compounds namely celecoxib, acetylsalicylic acid, rofecoxib. Therefore, all these small compounds reported from plant Litsea spp were found to possess potential medicinal values with anti-inflammatory properties.

  10. Nanoemulsion-based gel formulations of COX-2 inhibitors for enhanced efficacy in inflammatory conditions

    NASA Astrophysics Data System (ADS)

    Lala, R. R.; Awari, N. G.

    2013-01-01

    In the present study, we have investigated the potential of a nanoemulsion (thermodynamically stable transparent dispersions of oil and water having a droplet size <200 nm) formulation for the topical delivery of COX-2 inhibitors using etoricoxib as a model drug. Various oil-in-water nanoemulsions were prepared by the spontaneous emulsification method. The nanoemulsion area was identified by constructing pseudo-ternary phase diagrams. The prepared nanoemulsions were subjected to thermodynamic stability testing. Those that passed these tests were characterized for viscosity, droplet size and differential scanning calorimetry. Topical permeation of etoricoxib through porcine abdominal skin was estimated using the Franz diffusion cell. The ex vivo skin permeation profile of optimized formulations was compared with that of etoricoxib conventional gel. A significant increase in permeability was observed in optimized nanoemulsion formulations consisting of 2 % w/w of etoricoxib, 20 % w/w of Triacetin, 38 % w/w of a surfactant mixture (Cremophor RH 40:Transcutol P), and 42 % w/w of water. The anti-inflammatory effects of this formulation on carrageenan-induced paw edema in rats showed a significant increase in the percent inhibition value (84.61 % with the nanoemulsion gel and 92.30 % with the nanoemulsion) as compared with the conventional gel (69.23 %) after 6 h when compared with etoricoxib conventional gel. These results suggest that nanoemulsions can serve as potential vehicles for improved transdermal delivery of anti-inflammatory agents such as etoricoxib.

  11. Selective inhibition of COX-2 in humans is associated with less gastrointestinal injury: a comparison of nimesulide and naproxen

    PubMed Central

    Shah, A; Thjodleifsson, B; Murray, F; Kay, E; Barry, M; Sigthorsson, G; Gudjonsson, H; Oddsson, E; Price, A; Fitzgerald, D; Bjarnason, I

    2001-01-01

    BACKGROUND—Selective inhibitors of cyclooxygenase (COX)-2 may provoke less gastric damage and platelet inhibition than conventional non-steroidal anti-inflammatory drugs.
AIMS—We compared the biochemical and gastrointestinal effects of nimesulide, a potent and selective COX-2 inhibitor, with naproxen which exhibits no selectivity.
SUBJECTS—Thirty six healthy volunteers were randomised to nimesulide 100 mg or naproxen 500 mg twice daily for two weeks in a double blind, crossover study with a washout between treatments.
METHODS—Gastrointestinal side effects were assessed by endoscopy, and by estimation of small intestinal absorption-permeability and inflammation. Comparisons were made between variables at the end of each treatment phase.
RESULTS—Nimesulide caused significantly less gastric injury using the modified Lanza score (p<0.001) as well as reduced duodenum injury (p=0.039). Nimesulide had lower visual analogue scores (VAS) for haemorrhage and erosive lesions in the stomach (p<0.001) and for mucosal injection in the duodenum (p=0.039). Naproxen increased excretion of calprotectin, a marker of intestinal inflammation (5.5 (1.2) to 12.1 (2.1) mg/l) while nimesulide had no effect (treatment difference p=0.03). Naproxen abolished platelet aggregation to arachidonic acid and suppressed serum thromboxane B2 (TXB2) by 98%, indices of COX-1 activity. In contrast, nimesulide had no significant effect on platelet aggregation, although it reduced serum TXB2 by 29%. Production of prostaglandin E2 and prostacyclin by gastric biopsies, also COX-1 dependent, was inhibited by naproxen, but not by nimesulide. COX-2 activity, determined as endotoxin induced prostaglandin E2 formation in plasma, was markedly suppressed by both treatments.
INTERPRETATION—Nimesulide has preferential selectivity for COX-2 over COX-1 in vivo at full therapeutic doses and induces less gastrointestinal damage than that seen with naproxen in the short term

  12. Development of Antioxidant COX-2 Inhibitors as Radioprotective Agents for Radiation Therapy—A Hypothesis-Driven Review

    PubMed Central

    Laube, Markus; Kniess, Torsten; Pietzsch, Jens

    2016-01-01

    Radiation therapy (RT) evolved to be a primary treatment modality for cancer patients. Unfortunately, the cure or relief of symptoms is still accompanied by radiation-induced side effects with severe acute and late pathophysiological consequences. Inhibitors of cyclooxygenase-2 (COX-2) are potentially useful in this regard because radioprotection of normal tissue and/or radiosensitizing effects on tumor tissue have been described for several compounds of this structurally diverse class. This review aims to substantiate the hypothesis that antioxidant COX-2 inhibitors are promising radioprotectants because of intercepting radiation-induced oxidative stress and inflammation in normal tissue, especially the vascular system. For this, literature reporting on COX inhibitors exerting radioprotective and/or radiosensitizing action as well as on antioxidant COX inhibitors will be reviewed comprehensively with the aim to find cross-points of both and, by that, stimulate further research in the field of radioprotective agents. PMID:27104573

  13. COX-2 inhibitor celecoxib prevents chronic morphine-induced promotion of angiogenesis, tumour growth, metastasis and mortality, without compromising analgesia

    PubMed Central

    Farooqui, M; Li, Y; Rogers, T; Poonawala, T; Griffin, R J; Song, C W; Gupta, K

    2007-01-01

    Morphine and its congener opioids are the main therapy for severe pain in cancer. However, chronic morphine treatment stimulates angiogenesis and tumour growth in mice. We examined if celecoxib (a cyclooxygenase-2 (COX-2) inhibitor) prevents morphine-induced tumour growth without compromising analgesia. The effect of chronic treatment with celecoxib (by gavage) and/or morphine (subcutaneously), or PBS on tumour prostaglandin E2 (PGE2), COX-2, angiogenesis, tumour growth, metastasis, pain behaviour and survival was determined in a highly invasive SCK breast cancer model in A/J mice. Two weeks of chronic morphine treatment at clinically relevant doses stimulates COX-2 and PGE2 (4.5-fold compared to vehicle alone) and angiogenesis in breast tumours in mice. This is accompanied by increased tumour weight (∼35%) and increased metastasis and reduced survival. Co-administration of celecoxib prevents these morphine-induced effects. In addition, morphine and celecoxib together provided better analgesia than either agent alone. Celecoxib prevents morphine-induced stimulation of COX-2, PGE2, angiogenesis, tumour growth, metastasis and mortality without compromising analgesia in a murine breast cancer model. In fact, the combination provided significantly better analgesia than with morphine or celecoxib alone. Clinical trials of this combination for analgesia in chronic and severe pain in cancer are warranted. PMID:17971769

  14. A Controlled Trial of Chemoprevention Using COX-2 Inhibitors in an Avian Model of Spontaneous Ovarian Carcinogesis

    DTIC Science & Technology

    2006-03-01

    laying hen. The effect of varying doses of COX-2 inhibitor 4 on egg -laying activity as a surrogate marker for ovulatory frequency were also...personal communication: W. Berry) and the dramatic effect of decreased egg laying activity of Depo-Provera administered to similar laying hens (3...delivered to the hens. 5 hens were utilized per dose level for a total of 20 hens. The hens were monitored for egg laying activity as defined by

  15. The Effect of COX-2 Inhibitors on the Aromatase Gene (CYP19) Expression in Human Breast Cancer

    DTIC Science & Technology

    2006-12-01

    sulfa ” allergy. Drug Safety 2001; 24 (4), 239-247. 21. Patterson R, Bello A, Lefkowith J: Immunologic tolerability profile of celecoxib... drug is it is associated with less side effects than non- steroidal inflammatory drugs (NSAIDs), particularly gastroduodenal ulcers. Randomized...IIIB disease. 3.8 A woman who has received a COX-2 inhibitor, or NSAID within 7 days of study drug . 3.9 A women who is taking fluconazole, or

  16. Synthesis and biological evaluation of 3,4-diphenyl-1,2,5-oxadiazole-2-oxides and 3,4-diphenyl-1,2,5-oxadiazoles as potential hybrid COX-2 inhibitor/nitric oxide donor agents.

    PubMed

    Velázquez, Carlos; Rao, P N Praveen; McDonald, Robert; Knaus, Edward E

    2005-04-15

    A group of 3,4-diphenyl-1,2,5-oxadiazole-2-oxides (3,4-diphenylfuroxans) and the corresponding N-desoxy 3,4-diphenyl-1,2,5-oxadiazoles (3,4-diphenylfurazans) analogs, were synthesized for in vitro evaluation as hybrid cyclooxygenase (COX) inhibitor/nitric oxide donor agents. Reaction of 1-[4-(methylsulfonyl)phenyl]-2-phenylethene with an aqueous sodium nitrite solution in acetic acid afforded a mixture (3:1 ratio) of the inseparable 4-[4-(methylsulfonyl)phenyl]-3-phenyl-1,2,5-oxadiazole-2-oxide (13a) and 3-[4-(methylsulfonyl)phenyl]-4-phenyl-1,2,5-oxadiazole-2-oxide (13b) regioisomers. A group of related regioisomers possessing either a p-aminosulfonylphenyl (16) or a p-azidosulfonylphenyl (17), moiety were obtained by chlorosulfonation of the unsubstituted 3,4-diphenylfuroxan (10) and subsequent reaction with either ammonium hydroxide or sodium azide, respectively. The methanesulfonyl regioisomers 13a,b [COX-1 IC50=11.6 microM; COX-2 IC50=0.12 microM; COX-2 selectivity index (SI)=97] and aminosulfonyl regioisomers 16 (COX-1 IC50=9.8 microM; COX-2 IC50=0.78 microM; COX-2 SI=12), like the reference drug celecoxib (COX-1 IC50=33.1 microM; COX-2 IC50=0.07 microM; COX-2 SI=472), were potent in vitro COX-2 inhibitors with a good COX-2 selectivity index. Release of nitric oxide (NO) from the 3,4-diphenylfuroxan compounds (10, 13a,b, 16, 17) was thiol-dependent since the % NO released was higher upon incubation in the presence of l-cysteine (0.57-3.18%) compared to that in phosphate buffer solution at pH7.4 (0.06-0.15%). Molecular modeling (docking) studies show that the methanesulfonyl (MeSO2) COX-2 pharmacophore present in regioisomers 13a,b is positioned in the vicinity of the COX-2 secondary pocket. The in vitro NO release data, COX-1/COX-2 inhibition and COX-2 SI structure-activity relationships acquired, and molecular modeling docking studies suggest that the 1,2,5-oxadiazole-2-oxide (furoxan) ring possesses beneficial features that should be present in a suitable

  17. Recent Methodologies toward the Synthesis of Valdecoxib: A Potential 3,4-diarylisoxazolyl COX-2 Inhibitor

    PubMed Central

    Dadiboyena, Sureshbabu; Nefzi, Adel

    2011-01-01

    Non-steroidal anti-inflammatory drugs are widely used therapeutic agents in the treatment of inflammation, pain and fever. Cyclooxygenase catalyzes the initial step of biotransformation of arachidonic acid to prostanoids, and exist as three distinct isozymes; COX-I, COX-II and COX-III. Selective COX-II inhibitors are a class of potential anti-inflammatory, analgesic, and antipyretic drugs with reduced gastrointestinal (GI) side effects compared to nonselective inhibitors. 3,4-diarylisoxazole scaffold is recurrently found in a wide variety of NSAIDs, protein kinase inhibitors, hypertensive agents, and estrogen receptor (ER) modulators. In the present review, we document on the recent synthetic strategies of 3,4-diarylisoxazolyl scaffolds of valdecoxib and its relevant structural analogues. PMID:20724040

  18. Novel applications of COX-2 inhibitors, metformin, and statins for the primary chemoprevention of breast cancer

    PubMed Central

    Micallef, Darren; Micallef, Sarah; Schembri-Wismayer, Pierre; Calleja-Agius, Jean

    2016-01-01

    Recent evidence shows that commonly prescribed drugs, such as non-steroidal anti-inflammatory drugs (NSAIDs), metformin, and statins, may have beneficial roles in the primary chemoprevention of breast cancer. Therefore, these drugs could potentially be used in addition to the hormonal drugs currently used for this purpose (namely, selective estrogen receptor modulators and aromatase inhibitors) due to their alternative mechanisms of action. PMID:27990091

  19. COX-2 inhibitors from stem bark of Bauhinia rufescens Lam. (Fabaceae)

    PubMed Central

    Muhammad, Aminu; Sirat, Hasnah Mohd

    2013-01-01

    Chemical investigation of the stem bark of Bauhinia rufescens resulted in the isolation of a new cyanoglucoside and menisdaurin from methanol extract and oxepin from petroleum ether extract. The isolated compounds were tested for their anti-inflammatory potentials based on the cyclooxygenase-2 enzyme (COX-2) model. Cyanoglucoside exhibited the highest activity among the compounds with an inhibition activity of 49.34 % at 100 µM (IC50 0.46 µM) compared to the positive control, indomethacin (79.20 %, IC50 0.24 µM). PMID:26600739

  20. Effect of COX-2 inhibitors and other non-steroidal inflammatory drugs on breast cancer risk: a meta-analysis.

    PubMed

    de Pedro, María; Baeza, Sara; Escudero, María-Teresa; Dierssen-Sotos, Trinidad; Gómez-Acebo, Inés; Pollán, Marina; Llorca, Javier

    2015-01-01

    Evidence on non-steroidal anti-inflammatory drugs (NSAID) use and breast cancer risk shows a slightly protective effect of these drugs, but previous studies lack randomized clinical trial results and present high heterogeneity in exposure measurement. This systematic review and meta-analysis widens the knowledge about NSAID use and breast cancer risk, updating the information from the last meta-analysis, focusing on evidence on specific effects of COX-2 inhibitors and differential expression patterns of hormonal receptors. A PubMed-database search was conducted to include all entries published with the keywords "BREAST CANCER NSAID ANTI-INFLAMMATORY" until 10/24/2013 providing original results from cohort studies, case-control studies, or randomized clinical trials with at least one reported relative risk (RR) or odds ratio (OR) on the association between any NSAID use and incidence of invasive breast cancer. This resulted in 49 publications, from which the information was retrieved about type of study, exposure characteristics, breast cancer characteristics, and breast cancer-NSAID association. Meta-analyses were performed separately for case-control and cohort studies and for different hormone-receptor status. NSAID use reduced invasive breast cancer risk by about 20 %. A similar effect was found for aspirin, acetaminophen, COX-2 inhibitors and, to a lesser extent, ibuprofen. The effect of aspirin was similar in preventing hormone-receptor-positive breast cancer. This meta-analysis suggests a slightly protective effect of NSAIDs-especially aspirin and COX-2 inhibitors- against breast cancer, which seems to be restricted to ER/PR+tumors.

  1. Effect of structural modification of enol-carboxamide-type nonsteroidal antiinflammatory drugs on COX-2/COX-1 selectivity.

    PubMed

    Lazer, E S; Miao, C K; Cywin, C L; Sorcek, R; Wong, H C; Meng, Z; Potocki, I; Hoermann, M; Snow, R J; Tschantz, M A; Kelly, T A; McNeil, D W; Coutts, S J; Churchill, L; Graham, A G; David, E; Grob, P M; Engel, W; Meier, H; Trummlitz, G

    1997-03-14

    Meloxicam (5), an NSAID in the enol-carboxamide class, was developed on the basis of its antiinflammatory activity and relative safety in animal models. In subsequent screening in microsomal assays using human COX-1 and COX-2, we discovered that it possessed a selectivity profile for COX-2 superior to piroxicam and other marketed NSAIDs. We therefore embarked on a study of enol-carboxamide type compounds to determine if COX-2 selectivity and potency could be dramatically improved by structural modification. Substitution at the 6- and 7-positions of the 4-oxo-1,2-benzothiazine-3-carboxamide, alteration of the N-methyl substituent, and amide modification were all examined. In addition we explored several related systems including the isomeric 3-oxo-1,2-benzothiazine-4-carboxamides, thienothiazines, indolothizines, benzothienothiazines, naphthothiazines, and 1,3- and 1,4-dioxoisoquinolines. While a few examples were found with greater potency in the COX-2 assay, no compound tested had a better COX-2/COX-1 selectivity profile than that of 5.

  2. Effect of COX-2 inhibitor lumiracoxib and the TNF-α antagonist etanercept on TNBS-induced colitis in Wistar rats.

    PubMed

    Paiotti, Ana Paula Ribeiro; Ribeiro, Daniel Araki; Silva, Roseane Mendes; Marchi, Patrícia; Oshima, Celina Tizuko Fujiyama; Neto, Ricardo Artigiani; Miszputen, Sender Jankiel; Franco, Marcello

    2012-06-01

    Crohn's disease (CD) is associated with gut barrier dysfunction. Besides the baseline barrier defect, a subgroup of patients also expresses an intestinal barrier hyperresponsiveness to nonsteroidal anti-inflammatory drugs. On the other hand, the anti-tumour necrosis factor alpha (TNF-α) treatment has brought benefits to these patients. Thus, this study aimed to evaluate the effect of lumiracoxib, a selective-cyclooxygenase-2 (COX-2) inhibitor, and Etanercept (ETC), a TNF-α antagonist on the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis. A total of 47 Wistar rats were randomized into seven groups, as follows: (1) Sham: sham induced-colitis; (2) TNBS: nontreated induced-colitis; (3) Lumiracoxib control; (4) Lumiracoxib-treated induced-colitis; (5) ETC control; (6) ETC-treated induced-colitis; (7) Lumiracoxib-ETC-treated induced-colitis. Rats from groups 6 and 7 presented significant improvement of macroscopic and histopathological damages in the distal colon. The gene expression of COX-2 mRNA, as well of TNF-α mRNA, decreased significantly in groups 6 and 7 compared to the TNBS nontreated and lumiracoxib-treated groups. The treatment only with lumiracoxib did not reduce the inflammation on TNBS-induced experimental colitis. ETC attenuated the damage seen in the colon and reduced the inflammation caused by TNBS. Our results suggest that down-regulation of TNF-α and COX-2 resulted in a decrease in inflammation caused by TNBS and thus provided some protection from the colonic damage caused by TNBS.

  3. Antiproliferative diarylpyrazole derivatives as dual inhibitors of the ERK pathway and COX-2.

    PubMed

    El-Gamal, Mohammed I; Choi, Hong Seok; Yoo, Kyung Ho; Baek, Daejin; Oh, Chang-Hyun

    2013-09-01

    A series of 3,4-diarylpyrazole-1-carboxamide derivatives was designed and synthesized. A selected group of the target compounds was tested for in vitro antiproliferative activities over a panel of 60 cancer cell lines at the National Cancer Institute (NCI, Bethesda, MD, USA) at a single-dose concentration of 10 μm, and the four most active compounds 9a, 9l, 9n, and 10o were further tested in a five-dose testing mode to determine their IC50 values over the 60 cell lines. In addition, a selected group of target compounds were tested for inhibitory effect over cyclooxygenase isozymes. Compounds 9a, 9l, 9n, and 10o were also tested for MEK and ERK kinase inhibitory activity using Western blot assay. Compound 10o was selective toward melanoma cell line subpanel, and its antiproliferative activity may be attributed to selective cyclooxygenase-2 inhibition and ERK pathway inhibition.

  4. The Cox-2 Inhibitor Meloxicam Ameliorates Neuroinflammation and Depressive Behavior in Adult Mice after Splenectomy

    PubMed Central

    Haile, Michael; Boutajangout, Allal; Chung, Kevin; Chan, Jeffrey; Stolper, Tanya; Vincent, Nemahun; Batchan, Marc; D’Urso, John; Lin, Yan; Kline, Richard; Yaghmoor, Faris; Jahfal, Saad; Kamal, Robel; Aljohani, Waleed; Blanck, Thomas; Bekker, Alex; Wisniewski, Thomas

    2016-01-01

    Background Peripheral surgical trauma may incite neuroinflammation that leads to neuronal dysfunction associated with both depression and cognitive deficits. In a previous study, we found that adult mice developed neuroinflammation and short-term working memory dysfunction in a delayed, transient manner after splenectomy that was ameliorated by the cyclooxygenase-2 inhibitor meloxicam. We tested the hypothesis that splenectomy in mice would also cause anhedonia, the diminished response to pleasure or rewarding stimuli that is a hallmark of depression, and that treatment with meloxicam would be ameliorative. Methods After Institutional Animal Care and Use Committee approval, Swiss-Webster mice underwent sucrose preference training before being randomized into groups on day 0, when they had either splenectomy and anesthesia or anesthesia alone. Within each group, half were randomized to receive intraperitoneal saline at 24 hours, while the other half received intraperitoneal meloxicam at 24 hours. Sucrose preference ratios were determined on days 1, 5, 9, and 14. Additional mice were randomized into groups for brain histochemistry. Specimens were stained for glial fibrillary acidic protein (GFAP), a marker of astrocytes, and CD45, a protein tyrosine phosphatase that identifies microglial activation. Results On day 5, mice receiving splenectomy and saline demonstrated diminished sucrose preference, which was not seen in mice receiving splenectomy and meloxicam. Semiquantitative analysis of histological slides taken from splenectomized mice treated with meloxicam revealed reduced microglial-based neuroinflammation and reactive astrocytosis compared to mice receiving saline. Conclusion Splenectomy in mice is associated with neuroinflammation and anhedonia, as evidenced by reactive microgliosis, astrocytosis, and behavioral changes. Postsurgical treatment with meloxicam attenuates both neuroinflammation and anhedonia. These findings suggest that cyclooxygenase-2

  5. Adenosine signalling mediates the anti-inflammatory effects of the COX-2 inhibitor nimesulide.

    PubMed

    Caiazzo, Elisabetta; Maione, Francesco; Morello, Silvana; Lapucci, Andrea; Paccosi, Sara; Steckel, Bodo; Lavecchia, Antonio; Parenti, Astrid; Iuvone, Teresa; Schrader, Jürgen; Ialenti, Armando; Cicala, Carla

    2016-07-15

    Extracellular adenosine formation from ATP is controlled by ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase/CD39) and ecto-5'-nucleotidase (e-5NT/CD73); the latter converts AMP to adenosine and inorganic phosphate, representing the rate limiting step controlling the ratio between extracellular ATP and adenosine. Evidence that cellular expression and activity of CD39 and CD73 may be subject to changes under pathophysiological conditions has identified this pathway as an endogenous modulator in several diseases and was shown to be involved in the molecular mechanism of drugs, such as methotrexate, salicylates , interferon-β. We evaluated whether CD73/adenosine/A2A signalling pathway is involved in nimesulide anti-inflammatory effect, in vivo and in vitro. We found that the adenosine A2A agonist, 4-[2-[[6-amino-9-(N-ethyl-β-d-ribofuranuronamidosyl)-9H-purin-2-yl]amino]ethyl]benzenepropanoic acid hydrochloride (CGS21680, 2mg/kg ip.), inhibited carrageenan-induced rat paw oedema and the effect was reversed by co-administration of the A2A antagonist -(2-[7-amino-2-[2-furyl][1,2,4]triazolo[2,3-a][1,3,5]triazin-5-yl-amino]ethyl)phenol (ZM241385; 3mg/kg i.p.). Nimesulide (5mg/kg i.p.) anti-inflammatory effect was inhibited by pre-treatment with ZM241385 (3mg/kg i.p.) and by local administration of the CD73 inhibitor, adenosine 5'-(α,β-methylene)diphosphate (APCP; 400μg/paw). Furthermore, we found increased activity of 5'-nucleotidase/CD73 in paws and plasma of nimesulide treated rats, 4h following oedema induction. In vitro, the inhibitory effect of nimesulide on nitrite and prostaglandin E2 production by lipopolysaccharide-activated J774 cell line was reversed by ZM241385 and APCP. Furthermore, nimesulide increased CD73 activity in J774 macrophages while it did not inhibit nitrite accumulation by lipopolysaccharide-activated SiRNA CD73 silenced J774 macrophages. Our data demonstrate that the anti-inflammatory effect of nimesulide in part is mediated by CD73

  6. Design, synthesis, evaluation and molecular modelling studies of some novel 5,6-diphenyl-1,2,4-triazin-3(2H)-ones bearing five-member heterocyclic moieties as potential COX-2 inhibitors: A hybrid pharmacophore approach.

    PubMed

    Banerjee, Anupam G; Das, Nirupam; Shengule, Sushant A; Sharma, Piyoosh A; Srivastava, Radhey Shyam; Shrivastava, Sushant Kumar

    2016-12-01

    A series of novel hybrids comprising of 1,3,4-oxadiazole/thiadiazole and 1,2,4-triazole tethered to 5,6-diphenyl-1,2,4-triazin-3(2H)-one were designed, synthesised and evaluated as COX-2 inhibitors for the treatment of inflammation. The synthesised hybrids were characterised using FT-IR, 1H NMR, 13C NMR, elemental (C,H,N) analyses and assessed for their anti-inflammatory potential by in vitro albumin denaturation assay. Compounds exhibiting activity comparable to indomethacin and celecoxib were further evaluated for in vivo anti-inflammatory activity. Oral administration of promising compounds 3c-3e and 4c-4e did not evoke significant gastric, hepatic and renal toxicity in rats. These potential compounds exhibited reduced malondialdehyde (MDA) content on the gastric mucosa suggesting their protective effects by inhibition of lipid peroxidation. Based on the outcome of in vitro COX assay, compounds 3c-3e and 4c-4e (IC50 0.60-1.11μM) elicited an interesting profile as competitive selective COX-2 inhibitors. Further, selected compounds 3e and 4c were found devoid of cardiotoxicity post evaluation on myocardial infarcted rats. The in silico binding mode of the potential compounds into the COX-2 active site through docking and molecular dynamics exemplified their consensual interaction and subsequent COX-2 inhibition with significant implications for structure-based drug design.

  7. A review of the efficacy, safety, and cost-effectiveness of COX-2 inhibitors for Africa and the Middle East region.

    PubMed

    Zeidan, Anwar Z; Al Sayed, Bashar; Bargaoui, Naceur; Djebbar, Mourad; Djennane, Malik; Donald, Royden; El Deeb, Khamis; Joudeh, Raed A; Nabhan, Abdullah; Schug, Stephan A

    2013-04-01

    Despite an increasingly sophisticated understanding of pain mechanisms, acute and chronic pain remain undertreated throughout the world. This situation reflects the large gap that exists between evidence and practice in pain management and is typified by inappropriate use of nonsteroidal anti-inflammatory drugs (NSAIDs). The scientific evidence around these drugs continues to expand at a high rate, yet physicians are often unaware of best practice. To address this gap among physicians in Africa and the Middle East, an Expert Panel meeting was convened with representatives from the region. The principal objective of the meeting was to review the latest guidelines on the management of acute and chronic pain and to review the efficacy, safety, and cost-effectiveness of cyclooxygenase-2 (COX-2) inhibitors in these settings. The main outcome of this review process was a number of consensus statements concerning the definitions of acute and chronic pain, and the efficacy, safety and cost-effectiveness of traditional nonselective NSAIDs (nsNSAIDs) and selective COX-2 inhibitors (coxibs). The panel agreed that nsNSAIDs and coxibs are effective analgesics with similar efficacy for acute pain; for chronic musculoskeletal pain, NSAIDs are significantly more effective than either placebo or paracetamol. Coxibs offer important safety advantages over nsNSAIDs, including gastrointestinal safety and preservation of platelet function; notably, the cardiovascular safety of coxibs has been the subject of much recent debate. Furthermore, the panel agreed there is substantial evidence to indicate that cost savings can be achieved by using celecoxib in patients at moderate to high risk of gastrointestinal adverse events, even in countries with moderate healthcare expenditures.

  8. Structure Based Library Design (SBLD) for new 1,4-dihydropyrimidine scaffold as simultaneous COX-1/COX-2 and 5-LOX inhibitors.

    PubMed

    Lokwani, Deepak; Azad, Rajaram; Sarkate, Aniket; Reddanna, Pallu; Shinde, Devanand

    2015-08-01

    The various scaffolds containing 1,4-dihydropyrimidine ring were designed by considering the environment of the active site of COX-1/COX-2 and 5-LOX enzymes. The structure-based library design approach, including the focused library design (Virtual Combinatorial Library Design) and virtual screening was used to select the 1,4-dihydropyrimidine scaffold for simultaneous inhibition of both enzyme pathways (COX-1/COX-2 and 5-LOX). The virtual library on each 1,4-dihydropyrimidine scaffold was enumerated in two alternative ways. In first way, the chemical reagents at R groups were filtered by docking of scaffold with single position substitution, that is, only at R1, or R2, or R3, … Rn on COX-2 enzyme using Glide XP docking mode. The structures that do not dock well were removed and the library was enumerated with filtered chemical reagents. In second alternative way, the single position docking stage was bypassed, and the entire library was enumerated using all chemical reagents by docking on the COX-2 enzyme. The entire library of approximately 15,629 compounds obtained from both ways after screening for drug like properties, were further screened for their binding affinity against COX-1 and 5-LOX enzymes using Virtual Screening Workflow. Finally, 142 hits were obtained and divided into two groups based on their binding affinity for COX-1/COX-2 and for both enzyme pathways (COX-1/COX-2 and 5-LOX). The ten molecules were selected, synthesized and evaluated for their COX-1, COX-2 and 5-LOX inhibiting activity.

  9. Evidence for a central mode of action for etoricoxib (COX-2 inhibitor) in patients with painful knee osteoarthritis.

    PubMed

    Arendt-Nielsen, Lars; Egsgaard, Line Lindhardt; Petersen, Kristian Kjær

    2016-08-01

    The COX-2 inhibitor etoricoxib modulates the peripheral and central nociceptive mechanisms in animals. This interaction has not been studied in patients with pain. This randomized, double-blind, placebo-controlled, 2-way crossover, 4-week treatment study investigated the pain mechanisms modulated by etoricoxib in patients with painful knee osteoarthritis. Patients were randomized to group A (60 mg/d etoricoxib followed by placebo) or B (placebo followed by 60 mg/d etoricoxib). The quantitative, mechanistic pain biomarkers were pressure pain thresholds, temporal summation (TS), and conditioning pain modulation. Clinical readouts were Brief Pain Inventory, WOMAC, painDETECT questionnaire (PD-Q), and time and pain intensity during walking and stair climbing. Etoricoxib as compared with placebo significantly modulated the pressure pain thresholds (P = 0.012, localized sensitization) at the knee and leg (control site) (P = 0.025, spreading sensitization) and TS assessed from the knee (P = 0.038) and leg (P = 0.045). Conditioning pain modulation was not modulated. The Brief Pain Inventory (pain scores), PD-Q, WOMAC, and walking and stair climbing tests were all significantly improved by etoricoxib. Based on a minimum of 30% or 50% pain alleviation (day 0-day 28), responders and nonresponders were defined. The nonresponders showed a significant association between increased facilitation of TS and increased pain alleviation. None of the other parameters predicted the degree of pain alleviation. Generally, a responder to etoricoxib has the most facilitated TS. In conclusion, etoricoxib (1) modulated central pain modulatory mechanisms and (2) improved pain and function in painful osteoarthritis. Stronger facilitation of TS may indicate a better response to etoricoxib, supporting the central mode-of-action of the drug.

  10. AB036. Effects and its potential mechanisms of Cox-2 inhibitors on ejaculation latency of rat with experimental autoimmune prostatitis

    PubMed Central

    Zheng, Tao; Wang, Rui; Zhang, Tian-Biao; Jia, Dong-Hui; Wang, Chao-Liang; Sun, Yang; Zhang, Wei-Xing

    2016-01-01

    Background To investigate the effects and its potential mechanisms of Cox-2 inhibitors on ejaculation latency of rat with experimental autoimmune prostatitis (EAP). Methods Thirty six male Wistar rats with normal sexual function were screened by using the copulatory test, and were randomly divided into 3 groups: the model group (n=16), the normal control group (n=10) and the celecoxib treatment group (n=10). EAP rat model was established in the model group and the celecoxib treatment group by subcutaneous multiple point’s injection of male prostate gland extract emulsified in an equal volume of Freund’s adjuvant at the 0 and 21th day. Control animals received equal volume of saline. From the 0th day, the celecoxib treatment group was given a gavage of celecoxib (18 mg·kg-1·d-1), the model group and the normal control group were given a gavage of saline (0.1 mL·kg-1·d-1). Eight weeks later, the sexual behavior was investigated by the copulatory test, the morphological change of prostatic tissue was observed by light microscopy after HE staining, cytokines (TNF-α, IL-1β) in serum were detected by ELISA, the levels of 5-HT, 5-HT1A receptor, 5-HT2C receptor and SERT in T13-L2 and L5-S2 spinal cord tissue were detected by immunohistochemical staining and Western Blot. Results In model group, prostatic inflammation was found in 12 rats, and not in another 4 rats. The 4 rats were not included in the statistical analysis. In normal control group, prostatic inflammation was not found. In the celecoxib treatment group, there was a small amount of interstitial infiltration of inflammatory cells in rat’s prostate. In the copulatory test, compared with normal control group, mount latency (ML) and intromission latency (IL) in the model group were significantly prolonged (P<0.05); ejaculation latency (EL) in the model group was significantly shortened (P<0.05). There was no significant difference in these sexual behavior parameters between the normal control group and

  11. To Investigate the Therapeutic Efforts of the COX-2 Inhibitor NS-398 as a Single Agent, and in Combination with Vitamin D, in Vitro and in Vivo

    DTIC Science & Technology

    2008-01-01

    Combination with Vitamin D, in Vitro and in Vivo PRINCIPAL INVESTIGATOR: Yi-Fen Lee, Ph.D...NUMBER Single Agent, and in Combination with Vitamin D, in Vitro and in Vivo 5b. GRANT NUMBER W81XWH-05-1-0121 5c. PROGRAM ELEMENT NUMBER...progression. We have identified a cross-talk between vitamin D and COX-2 inhibitor, two chemopreventative agents for prostate cancer, and conducted series

  12. Constitutively expressed COX-2 in osteoblasts positively regulates Akt signal transduction via suppression of PTEN activity.

    PubMed

    Li, Ching-Ju; Chang, Je-Ken; Wang, Gwo-Jaw; Ho, Mei-Ling

    2011-02-01

    Cyclooxygenase-2 (COX-2) is thought to be an inducible enzyme, but increasing reports indicate that COX-2 is constitutively expressed in several organs. The status of COX-2 expression in bone and its physiological role remains undefined. Non-selective non-steroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 inhibitors, which commonly suppress COX-2 activity, were reported to suppress osteoblast proliferation via Akt/FOXO3a/p27(Kip1) signaling, suggesting that COX-2 may be the key factor of the suppressive effects of NSAIDs on proliferation. Although Akt activation correlates with PTEN deficiency and cell viability, the role of COX-2 on PTEN/Akt regulation remains unclear. In this study, we hypothesized that COX-2 may be constitutively expressed in osteoblasts and regulate PTEN/Akt-related proliferation. We examined the localization and co-expression of COX-2 and p-Akt in normal mouse femurs and in cultured mouse (mOBs) and human osteoblasts (hOBs). Our results showed that osteoblasts adjacent to the trabeculae, periosteum and endosteum in mouse femurs constitutively expressed COX-2, while COX-2 co-expressed with p-Akt in osteoblasts sitting adjacent to trabeculae in vivo, and in mOBs and hOBs in vitro. We further used COX-2 siRNA to test the role of COX-2 in Akt signaling in hOBs; COX-2 silencing significantly inhibited PTEN phosphorylation, enhanced PTEN activity, and suppressed p-Akt level and proliferation. However, replenishment of the COX-2 enzymatic product, PGE2, failed to reverse COX-2-dependent Akt phosphorylation. Furthermore, transfection with recombinant human COX-2 (rhCOX-2) significantly reversed COX-2 siRNA-suppressed PTEN phosphorylation, but this effect was reduced when the enzymatic activity of rhCOX-2 was blocked. This finding indicated that the effect of COX-2 on PTEN/Akt signaling is not related to PGE2 but still dependent on COX-2 enzymatic activity. Conversely, COX-1 silencing did not affect PTEN/Akt signaling. Our findings provide

  13. Targeting Estrogen-Induced COX-2 Activity in Lymphangioleiomyomatosis (LAM)

    DTIC Science & Technology

    2014-12-01

    Lymphangioleiomyomatosis (LAM), prostaglandin biosynthesis, cyclooxygenase-2 (COX-2), COX-2 inhibitors, xenograft tumors, bioluminescent imaging...Lymphangioleiomyomatosis (LAM), prostaglandin biosynthesis, cyclooxygenase-2 (COX-2), COX-2 inhibitors, xenograft tumors, bioluminescent imaging...TSC2- null cells. We found that aspirin treatment for three weeks decreased the intensity of bioluminescence , Page 5 of 8 and decreased the

  14. The impact of the cox-2 inhibitor issue on perceptions of the pharmaceutical industry: content analysis and communication implications.

    PubMed

    Lofstedt, Ragnar E

    2007-01-01

    The field of risk communication has its roots in the environmental, chemical, space, and nuclear arenas. As a number of these sectors have now vastly improved their communication strategies, attention is being placed on sectors that have been more problematic as of late. Examples of such sectors, include the food industries and the pharmaceutical/health sector. This article focuses on how large, multinational pharmaceutical companies can better communicate risks by analysis of one specific case, namely, that of the Cox-2 controversy.(1) For purposes of this article, risk communication is best described as "the flow of information and risk evaluations back and forth between academic experts, regulatory practitioners, interest groups and the general public," and "big pharma" refers to the more traditional R & D-based, innovative pharmaceutical companies.

  15. Antitumor activity of the MEK inhibitor trametinib on intestinal polyp formation in ApcΔ716 mice involves stromal COX-2

    PubMed Central

    Fujishita, Teruaki; Kajino-Sakamoto, Rie; Kojima, Yasushi; Taketo, Makoto Mark; Aoki, Masahiro

    2015-01-01

    Extracellular signal-regulated kinase is an MAPK that is most closely associated with cell proliferation, and the MEK/ERK signaling pathway is implicated in various human cancers. Although epidermal growth factor receptor, KRAS, and BRAF are considered major targets for colon cancer treatment, the precise roles of the MEK/ERK pathway, one of their major downstream effectors, during colon cancer development remain to be determined. Using ApcΔ716 mice, a mouse model of familial adenomatous polyposis and early-stage sporadic colon cancer formation, we show that MEK/ERK signaling is activated not only in adenoma epithelial cells, but also in tumor stromal cells including fibroblasts and vascular endothelial cells. Eight-week treatment of ApcΔ716 mice with trametinib, a small-molecule MEK inhibitor, significantly reduced the number of polyps in the large size class, accompanied by reduced angiogenesis and tumor cell proliferation. Trametinib treatment reduced the COX-2 level in ApcΔ716 tumors in vivo and in primary culture of intestinal fibroblasts in vitro. Antibody array analysis revealed that trametinib and the COX-2 inhibitor rofecoxib both reduced the level of CCL2, a chemokine known to be essential for the growth of Apc mutant polyps, in intestinal fibroblasts in vitro. Consistently, trametinib treatment reduced the Ccl2 mRNA level in ApcΔ716 tumors in vivo. These results suggest that MEK/ERK signaling plays key roles in intestinal adenoma formation in ApcΔ716 mice, at least in part, through COX-2 induction in tumor stromal cells. PMID:25855137

  16. Role of LKB1-CRTC1 on Glycosylated COX-2 and Response to COX-2 Inhibition in Lung Cancer

    PubMed Central

    Cao, Chunxia; Gao, Ruli; Zhang, Min; Amelio, Antonio L.; Fallahi, Mohammad; Chen, Zirong; Gu, Yumei; Hu, Chengbin; Welsh, Eric A.; Engel, Brienne E.; Haura, Eric B.; Cress, W. Douglas; Wu, Lizi; Zajac-Kaye, Maria

    2015-01-01

    Background: Cyclooxygenase-2 (COX-2) directs the synthesis of prostaglandins including PGE-2 linking inflammation with mitogenic signaling. COX-2 is also an anticancer target, however, treatment strategies have been limited by unreliable expression assays and by inconsistent tumor responses to COX-2 inhibition. Methods: We analyzed the TCGA and Director’s Challenge lung cancer datasets (n = 188) and also generated an LKB1-null lung cancer gene signature (n = 53) to search the Broad Institute/Connectivity-MAP (C-MAP) dataset. We performed ChIP analyses, real-time polymerase chain reaction, immunoblotting, and drug testing of tumor cell lines (n = 8) and primary lung adenocarcinoma surgical resections (n = 13). Results: We show that COX-2 is a target of the cAMP/CREB coactivator CRTC1 signaling pathway. In addition, we detected a correlation between LKB1 status, CRTC1 activation, and presence of glycosylated, but not inactive hypoglycosylated COX-2 in primary lung adenocarcinoma. A search of the C-MAP drug database discovered that all high-ranking drugs positively associated with the LKB1-null signature are known CRTC1 activators, including forskolin and six different PGE-2 analogues. Somatic LKB1 mutations are present in 20.0% of lung adenocarcinomas, and we observed growth inhibition with COX-2 inhibitors in LKB1-null lung cancer cells with activated CRTC1 as compared with LKB1-wildtype cells (NS-398, P = .002 and Niflumic acid, P = .006; two-tailed t test). Conclusion: CRTC1 activation is a key event that drives the LKB1-null mRNA signature in lung cancer. We also identified a positive feedback LKB1/CRTC1 signaling loop for COX-2/PGE2 regulation. These data suggest a role for LKB1 status and glycosylated COX-2 as specific biomarkers that provide a framework for selecting patients for COX-2 inhibition studies. PMID:25465874

  17. Combined treatment with the Cox-2 inhibitor niflumic acid and PPARγ ligand ciglitazone induces ER stress/caspase-8-mediated apoptosis in human lung cancer cells.

    PubMed

    Kim, Byeong Mo; Maeng, Kyungah; Lee, Kee-Ho; Hong, Sung Hee

    2011-01-28

    The present study was performed to investigate the possible combined use of the Cox-2 inhibitor niflumic acid and the PPARγ ligand ciglitazone and to elucidate the mechanisms underlying enhanced apoptosis by this combination treatment in human lung cancer cells. Combined niflumic acid-ciglitazone treatment synergistically induced apoptotic cell death, activated caspase-9, caspase-3, and induced caspase-3-mediated PARP cleavage. The combination treatment also triggered apoptosis through caspase-8/Bid/Bax activation, and the inhibition of caspase-8 suppressed caspase-8/Bid activation, caspase-3-mediated PARP cleavage, and concomitant apoptosis. In addition, combined niflumic acid-ciglitazone treatment significantly induced ER stress responses, and suppression of CHOP expression significantly attenuated the combined niflumic acid-ciglitazone treatment-induced activation of caspase-8 and caspase-3, and the subsequent apoptotic cell death, indicating a role of ER stress in caspase-8 activation and apoptosis. Interestingly, the pro-apoptotic effects of combined niflumic acid-ciglitazone treatment were realized through Cox-2- and PPARγ-independent mechanisms. Taken together, these results suggest that sequential ER stress and caspase-8 activation are critical in combined niflumic acid-ciglitazone treatment-induced apoptosis in human lung cancer cells.

  18. COX-2 mRNA expression in esophageal squamous cell carcinoma (ESCC) and effect by NSAID.

    PubMed

    Liu, X; Li, P; Zhang, S-T; You, H; Jia, J-D; Yu, Z-L

    2008-01-01

    To investigate cyclooxygenase-2 (COX-2) mRNA expression in human esophageal squamous cell carcinoma and the effect of a non-steroidal anti-inflammatory drug (NSAID) on it, in order to explore the mechanism of COX-2 in esophageal squamous cell carcinoma (ESCC) carcinogenesis and the ability of NSAID to prevent or treat ESCC. Frozen specimens of human ESCC and adjacent normal esophageal squamous epithelium pairs (n = 22) were examined for COX-2 mRNA expression by reverse-transcription polymerase chain reaction (RT-PCR). After incubation with aspirin (a non-selective COX inhibitor) or Nimesulide (a selective COX-2 inhibitor), the proliferation status of two human esophageal squamous cancer cell lines, EC-9706 and EC-109, was quantified by 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide assay. The expression of COX-2 mRNA in these cells was detected by RT-PCR. COX-2 mRNA was expressed in 12 of 22 (54.5%) ESCC tissue samples, but it was undetectable in all the specimens of adjacent normal esophageal squamous epithelium COX-2 mRNA expression. Both aspirin (5-20 mmol/L) and Nimesulide (0.1-0.8 mmol/L) inhibited EC-9706 cell line proliferation and suppressed its COX-2 mRNA expression dose-dependently. However, only aspirin (5-20 mmol/L) could inhibit proliferation in the EC-109 cell line and suppress COX-2 mRNA expression. Nimesulide (0.1-0.8 mmol/L) could neither inhibit EC-109 cell growth nor suppress COX-2 mRNA expression. COX-2 mRNA expression is a frequent phenomenon in human ESCC tissue samples and plays an important role in the carcinogenesis of ESCC. NSAID may be useful in the chemoprevention and therapy of human ESCC and its effects are likely to be mediated by modulating COX-2 activity.

  19. COX-2 inhibitor prevents tumor induced down regulation of classical DC lineage specific transcription factor Zbtb46 resulting in immunocompetent DC and decreased tumor burden.

    PubMed

    Pandey, Vipul K; Amin, Prayag J; Shankar, Bhavani S

    2017-04-01

    The interaction between the immune and tumor cells in the microenvironment is an important factor deciding the progression of cancer. Though many of the soluble mediators in the microenvironment that mediate immunosuppression are known, the mechanism by which the tumor affects the distal progenitors is not known. We report that the tumor derived prostanoids down regulated classical dendritic cells DC (cDC) lineage specific transcription factor Zbtb46 in the progenitor cells which affects its differentiation. Prostanoids also induced ERK/CREB/IL-10 signaling pathway in DC that is more important for maturation of DC. This was observed under in vitro as well as in vivo conditions leading to phenotypic and functional impairment of DC. siRNA mediated knockdown of Zbtb46 and not exogenous IL-10 mimicked the effects of tumor conditioned medium (TCM) on suppression of maturation markers. Treatment of tumor cells with COX-2 inhibitor NS-398 averted TCM induced phenotypic impairment of DC in vitro. Treatment of tumor bearing mice with NS-398 prevented tumor induced down regulation of Zbtb46 resulting in immunocompetent DC which in turn led to a decrease in tumor burden. The effects of NS-398 was indeed through immunomodulation was corroborated by no such response in SCID mice. Our study provides novel insight into the distal regulation of progenitor cells by tumor and the importance of Zbtb46 expression in anti-tumor immunity. These results identify Zbtb46 expression as an indicator of immunocompetent DC in tumor and also highlights that COX-2 inhibitors could be useful in cancer immunotherapy.

  20. Targeting inhibition of COX-2: a review of patents, 2002-2006.

    PubMed

    da Cunha, Elaine F F; Ramalho, Teodorico C; Josa, Daniela; Caetano, Melissa S; de Souza, Thaís C S

    2007-06-01

    The main COX inhibitors are the non-steroidal anti-inflammatory drugs (NSAIDs). NSAIDs exert anti-inflammatory and analgesic effects through the inhibition of prostaglandin synthesis by blocking COX activity. Currently two COX isoenzymes are known, COX-1 and COX-2. Prostaglandins influenced by COX-1 maintain the integrity of the gastric mucosa. On the other hand, prostaglandins influenced by COX-2 mediate the inflammatory process. The common anti-inflammatory drugs (like aspirin, ibuprofen, and naproxen) all act by blocking the action of both the COX-1 and COX-2 enzymes. The COX-2 inhibitors represent a new class of drugs that do not affect COX-1, but selectively block COX-2. This selective action provides the benefits of reducing inflammation without irritating the stomach. This review will focus on the most recent developments published in the field, paying particular attention to promising COX-2 inhibitors, their chemistry and biological evaluation, and to new chemical and pharmaceutical processes. Moreover, we will discuss recent patents of structural analogs of the COX-2 inhibitors celecoxib and valdecoxib, and novel potential pyridazine, triazole, indole, thione derivatives as a future target for the treatment of inflammation, pain and other diseases.

  1. Viscum album-Mediated COX-2 Inhibition Implicates Destabilization of COX-2 mRNA

    PubMed Central

    Saha, Chaitrali; Hegde, Pushpa; Friboulet, Alain; Bayry, Jagadeesh; Kaveri, Srinivas V.

    2015-01-01

    Extensive use of Viscum album (VA) preparations in the complementary therapy of cancer and in several other human pathologies has led to an increasing number of cellular and molecular approaches to explore the mechanisms of action of VA. We have recently demonstrated that, VA preparations exert a potent anti-inflammatory effect by selectively down-regulating the COX-2-mediated cytokine-induced secretion of prostaglandin E2 (PGE2), one of the important molecular signatures of inflammatory reactions. In this study, we observed a significant down-regulation of COX-2 protein expression in VA-treated A549 cells however COX-2 mRNA levels were unaltered. Therefore, we hypothesized that VA induces destabilisation of COX-2 mRNA, thereby depleting the available functional COX-2 mRNA for the protein synthesis and for the subsequent secretion of PGE2. To address this question, we analyzed the molecular degradation of COX-2 protein and its corresponding mRNA in A549 cell line. Using cyclohexamide pulse chase experiment, we demonstrate that, COX-2 protein degradation is not affected by the treatment with VA whereas experiments on transcriptional blockade with actinomycin D, revealed a marked reduction in the half life of COX-2 mRNA due to its rapid degradation in the cells treated with VA compared to that in IL-1β-stimulated cells. These results thus demonstrate that VA-mediated inhibition of PGE2 implicates destabilization of COX-2 mRNA. PMID:25664986

  2. Sinomenine, a COX-2 inhibitor, induces cell cycle arrest and inhibits growth of human colon carcinoma cells in vitro and in vivo

    PubMed Central

    YANG, HAIBO; YIN, PEIHAO; SHI, ZHAN; MA, YANCHUN; ZHAO, CHENGGEN; ZHENG, JAMPU; CHEN, TENG

    2016-01-01

    Certain non-steroidal anti-inflammatory drugs may possess anti-tumorigenic effects in certain cancer cell types. Sinomenine (SIN) is an alkaloid from Sinomenium acutum, a Chinese medicinal plant that inhibits inflammatory reactions and that has been used in the treatment of neuralgia and rheumatic diseases. In this study, we investigated the anticancer effects of SIN against colorectal cancer in vitro and in vivo, as well as the underlying mechanisms. The effects of SIN on proliferation, cell cycle progression and cyclooxygenase (COX)-2 expression were examined in human colorectal cancer-derived SW1116 cells. The in vivo effects of SIN were examined in a model of SW1116 tumor xenograft growth in athymic nude mice. Changes in COX-2 expression induced by the biological effects of SIN were analyzed by western blot analysis. The effects of SIN treatment on G1 phase cell cycle regulators in xenografts were analyzed by immunohistochemistry. Our findings demonstrate that SIN inhibits the proliferation of SW1116 cells by promoting their accumulation in the G1 phase, with concomitant suppression of COX-2 expression. Time- and dose-dependent inhibition of tumor growth and reduced toxicity were observed in nude mice administered daily intraperitoneal injections of SIN at doses of 25, 50 and 100 mg/kg. SIN-treated tumors also exhibited reduced COX-2 expression, a marked increase in Cip1/p21 protein levels and a decrease in the levels of cyclin D1 and cyclin E. SIN may be an effective chemopreventive agent against colorectal cancer. The growth inhibitory properties of SIN against colorectal cancer may be mediated via a COX-2 inhibitory effect and cell cycle arrest in the G1 phase. PMID:26870226

  3. Sinomenine, a COX-2 inhibitor, induces cell cycle arrest and inhibits growth of human colon carcinoma cells in vitro and in vivo.

    PubMed

    Yang, Haibo; Yin, Peihao; Shi, Zhan; Ma, Yanchun; Zhao, Chenggen; Zheng, Jampu; Chen, Teng

    2016-01-01

    Certain non-steroidal anti-inflammatory drugs may possess anti-tumorigenic effects in certain cancer cell types. Sinomenine (SIN) is an alkaloid from Sinomenium acutum, a Chinese medicinal plant that inhibits inflammatory reactions and that has been used in the treatment of neuralgia and rheumatic diseases. In this study, we investigated the anticancer effects of SIN against colorectal cancer in vitro and in vivo, as well as the underlying mechanisms. The effects of SIN on proliferation, cell cycle progression and cyclooxygenase (COX)-2 expression were examined in human colorectal cancer-derived SW1116 cells. The in vivo effects of SIN were examined in a model of SW1116 tumor xenograft growth in athymic nude mice. Changes in COX-2 expression induced by the biological effects of SIN were analyzed by western blot analysis. The effects of SIN treatment on G1 phase cell cycle regulators in xenografts were analyzed by immunohistochemistry. Our findings demonstrate that SIN inhibits the proliferation of SW1116 cells by promoting their accumulation in the G1 phase, with concomitant suppression of COX-2 expression. Time- and dose-dependent inhibition of tumor growth and reduced toxicity were observed in nude mice administered daily intraperitoneal injections of SIN at doses of 25, 50 and 100 mg/kg. SIN-treated tumors also exhibited reduced COX-2 expression, a marked increase in Cip1/p21 protein levels and a decrease in the levels of cyclin D1 and cyclin E. SIN may be an effective chemopreventive agent against colorectal cancer. The growth inhibitory properties of SIN against colorectal cancer may be mediated via a COX-2 inhibitory effect and cell cycle arrest in the G1 phase.

  4. Docking studies on NSAID/COX-2 isozyme complexes using Contact Statistics analysis

    NASA Astrophysics Data System (ADS)

    Ermondi, Giuseppe; Caron, Giulia; Lawrence, Raelene; Longo, Dario

    2004-11-01

    The selective inhibition of COX-2 isozymes should lead to a new generation of NSAIDs with significantly reduced side effects; e.g. celecoxib (Celebrex®) and rofecoxib (Vioxx®). To obtain inhibitors with higher selectivity it has become essential to gain additional insight into the details of the interactions between COX isozymes and NSAIDs. Although X-ray structures of COX-2 complexed with a small number of ligands are available, experimental data are missing for two well-known selective COX-2 inhibitors (rofecoxib and nimesulide) and docking results reported are controversial. We use a combination of a traditional docking procedure with a new computational tool (Contact Statistics analysis) that identifies the best orientation among a number of solutions to shed some light on this topic.

  5. Cell Intrinsic Role of Cox-2 in Pancreatic Cancer Development

    PubMed Central

    Hill, Reginald; Li, Yunfeng; Tran, Linh M.; Dry, Sarah; Calvopina, Joseph Hargan; Garcia, Alejandro; Kim, Christine; Wang, Ying; Donahue, Timothy R.; Herschman, Harvey R.; Wu, Hong

    2012-01-01

    Cyclooxygenase-2 (COX-2) is upregulated in pancreatic ductal adenocarcinomas (PDAC). However, how COX-2 promotes PDAC development is unclear. While previous studies have evaluated the efficacy of COX-2 inhibition via the use of non steroidal anti-inflammatory drugs (NSAIDs) or the COX-2 inhibitor celecoxib in PDAC models, none have addressed the cell intrinsic vs. microenvironment roles of COX-2 in modulating PDAC initiation and progression. We tested the cell intrinsic role of COX-2 in PDAC progression, using both loss-of-function and gain-of-function approaches. Cox-2 deletion in Pdx1+ pancreatic progenitor cells significantly delays the development of PDAC in mice with K-ras activation and Pten haploinsufficiency. Conversely, COX-2 over-expression promotes early onset and progression of PDAC in the K-ras mouse model. Loss of PTEN function is a critical factor in determining lethal PDAC onset and overall survival. Mechanistically, COX-2 over-expression increases P-AKT levels in the precursor lesions of Pdx1+;K-rasG12D/+;Ptenlox/+ mice in the absence of Pten LOH. In contrast, Cox-2 deletion in the same setting diminishes P-AKT levels and delays cancer progression. These data suggest an important cell intrinsic role for COX-2 in tumor initiation and progression through activation of the PI3K/AKT pathway. PDAC that is independent of intrinsic COX-2 expression eventually develops with decreased FKBP5 and increased GRP78 expression, two alternate pathways leading to AKT activation. Together, these results support a cell intrinsic role for COX-2 in PDAC development and suggest that, while anti-COX-2 therapy may delay the development and progression of PDAC, mechanisms known to increase chemoresistance through AKT activation must also be overcome. PMID:22784710

  6. The novel anti-inflammatory agent VA694, endowed with both NO-releasing and COX2-selective inhibiting properties, exhibits NO-mediated positive effects on blood pressure, coronary flow and endothelium in an experimental model of hypertension and endothelial dysfunction.

    PubMed

    Martelli, A; Testai, L; Anzini, M; Cappelli, A; Di Capua, A; Biava, M; Poce, G; Consalvi, S; Giordani, A; Caselli, G; Rovati, L; Ghelardini, C; Patrignani, P; Sautebin, L; Breschi, M C; Calderone, V

    2013-12-01

    Selective cyclooxygenase 2 (COX2) inhibitors (COXIBs) are effective anti-inflammatory and analgesic drugs with improved gastrointestinal (GI) safety compared to nonselective nonsteroidal anti-inflammatory drugs known as traditional (tNSAIDs). However, their use is associated with a cardiovascular (CV) hazard (i.e. increased incidence of thrombotic events and hypertension) due to the inhibition of COX2-dependent vascular prostacyclin. Aiming to design COX2-selective inhibitors with improved CV safety, new NO-releasing COXIBs (NO-COXIBs) have been developed. In these hybrid drugs, the NO-mediated CV effects are expected to compensate for the COXIB-mediated inhibition of prostacyclin. This study evaluates the potential CV beneficial effects of VA694, a promising NO-COXIB, the anti-inflammatory effects of which have been previously characterized in several in vitro and in vivo experimental models. When incubated in hepatic homogenate, VA694 acted as a slow NO-donor. Moreover, it caused NO-mediated relaxant effects in the vascular smooth muscle. The chronic oral administration of VA694 to young spontaneously hypertensive rats (SHRs) significantly slowed down the age-related development of hypertension and was associated with increased plasma levels of nitrates, stable end-metabolites of NO. Furthermore, a significant improvement of coronary flow and a significant reduction of endothelial dysfunction were observed in SHRs submitted to chronic administration of VA694. In conclusion, VA694 is a promising COX2-inhibiting hybrid drug, showing NO releasing properties which may mitigate the CV deleterious effects associated with the COX2-inhibition.

  7. COX-2 is involved in ET-1-induced hypertrophy of neonatal rat cardiomyocytes: role of NFATc3.

    PubMed

    Li, Hong; Gao, Si; Ye, Jiantao; Feng, Xiaojun; Cai, Yi; Liu, Zhiping; Lu, Jing; Li, Qin; Huang, Xiaoyang; Chen, Shaorui; Liu, Peiqing

    2014-02-15

    Endothelin-1 (ET-1) is a critical molecule that involved in heart failure. It has been proved that ET-1 stimulation results in cardiac hypertrophy both in vitro and in vivo, but the mechanisms underlying remain largely unknown. In this study, we reported that cyclooxygenase-2 (COX-2) might be an important mediator of hypertrophic responses to ET-1 stimulation. In the cultured rat neonatal cardiomyocytes, ET-1 significantly upregulated the expression and activity of COX-2, which was accompanied by increase in cell surface area and BNP mRNA level. In contrast, ET-1-dependent cardiomyocyte hypertrophy was abolished by COX-2 selective inhibitors, NS-398 and celecoxib, or by COX-2 RNA interference, but the inhibitory effects could be diminished by pretreatment with PGE2. Furthermore, cyclosporin A (CsA) and knockdown of nuclear factor of activated T-cells c3 (NFATc3) inhibited the expression of COX-2 induced by ET-1, and NFATc3 could also bound to the -GGAAA- sequence in the promoter region of rat COX-2 gene, indicating that calcineurin/NFATc3 signaling participated in the transcriptional regulation of COX-2 following ET-1 treatment. These findings provided further insight into the roles of ET-1 in cardiac hypertrophy and suggested a potential therapeutic strategy against cardiac hypertrophy by inhibiting COX-2.

  8. COX2 and PGE2 mediate EGF-induced E-cadherin-independent human ovarian cancer cell invasion.

    PubMed

    Qiu, Xin; Cheng, Jung-Chien; Chang, Hsun-Ming; Leung, Peter C K

    2014-08-01

    Elevated expression of cyclooxygenase 2 (COX2 (PTGS2)) has been reported to occur in human ovarian cancer and to be associated with poor prognosis. We have previously demonstrated that COX2-derived prostaglandin E2 (PGE2) promotes human ovarian cancer cell invasion. We had also demonstrated that epidermal growth factor (EGF) induces human ovarian cancer cell invasion by downregulating the expression of E-cadherin through various signaling pathways. However, it remains unclear whether COX2 and PGE2 are involved in the EGF-induced downregulation of E-cadherin expression and cell invasion in human ovarian cancer cells. In this study, we showed that EGF treatment induces COX2 expression and PGE2 production in SKOV3 and OVCAR5 human ovarian cancer cell lines. Interestingly, COX2 is not required for the EGF-induced downregulation of E-cadherin expression. In addition, EGF treatment activates the phosphatidylinositol-3-kinase (PI3K)/Akt and cAMP response element-binding protein (CREB) signaling pathways, while only the PI3K/Akt pathway is involved in EGF-induced COX2 expression. Moreover, we also showed that EGF-induced cell invasion is attenuated by treatment with a selective COX2 inhibitor, NS-398, as well as PGE2 siRNA. This study demonstrates an important role for COX2 and its derivative, PGE2, in the mediation of the effects of EGF on human ovarian cancer cell invasion.

  9. Increased dietary sodium induces COX2 expression by activating NFκB in renal medullary interstitial cells.

    PubMed

    He, Wenjuan; Zhang, Min; Zhao, Min; Davis, Linda S; Blackwell, Timothy S; Yull, Fiona; Breyer, Matthew D; Hao, Chuan-Ming

    2014-02-01

    High salt diet induces renal medullary cyclooxygenase 2 (COX2) expression. Selective blockade of renal medullary COX2 activity in rats causes salt-sensitive hypertension, suggesting a role for renal medullary COX2 in maintaining systemic sodium balance. The present study characterized the cellular location of COX2 induction in the kidney of mice following high salt diet and examined the role of NFκB in mediating this COX2 induction in response to increased dietary salt. High salt diet (8 % NaCl) for 3 days markedly increased renal medullary COX2 expression in C57Bl/6 J mice. Co-immunofluorescence using a COX2 antibody and antibodies against aquaporin-2, ClC-K, aquaporin-1, and CD31 showed that high salt diet-induced COX2 was selectively expressed in renal medullary interstitial cells. By using NFκB reporter transgenic mice, we observed a sevenfold increase of luciferase activity in the renal medulla of the NFκB-luciferase reporter mice following high salt diet, and a robust induction of enhanced green fluorescent protein (EGFP) expression mainly in renal medullary interstitial cells of the NFκB-EGFP reporter mice following high salt diet. Treating high salt diet-fed C57Bl/6 J mice with selective IκB kinase inhibitor IMD-0354 (8 mg/kg bw) substantially suppressed COX2 induction in renal medulla, and also significantly reduced urinary prostaglandin E2 (PGE2). These data therefore suggest that renal medullary interstitial cell NFκB plays an important role in mediating renal medullary COX2 expression and promoting renal PGE2 synthesis in response to increased dietary sodium.

  10. Increased Dietary Sodium Induces COX2 Expression by activating NFκB in Renal Medullary Interstitial Cells

    PubMed Central

    Zhao, Min; Davis, Linda S.; Blackwell, Timothy S.; Yull, Fiona; Breyer, Matthew D.; Hao, Chuan-Ming

    2013-01-01

    High salt diet induces renal medullary COX2 expression. Selective blockade of renal medullary COX2 activity in rats causes salt sensitive hypertension, suggesting a role for renal medullary COX2 in maintaining systemic sodium balance. The present study characterized the cellular location of COX2 induction in the kidney of mice following high salt diet and examined the role of NFκB in mediating this COX2 induction in response to increased dietary salt. High salt diet (8% NaCl) for 3 days markedly increased renal medullary COX2 expression in C57Bl/6J mice. Co-immunofluorescence using a COX2 antibody and antibodies against AQP2, ClC-K, AQP1 and CD31 showed that high salt diet-induced COX2 was selectively expressed in renal medullary interstitial cells. By using NFκB reporter transgenic mice, we observed a 7 fold increase of luciferase activity in the renal medulla of the NFκB-luciferase reporter mice following high salt diet, and a robust induction of EGFP expression mainly in renal medullary interstitial cells of the NFκB-EGFP reporter mice following high salt diet. Treating high salt diet fed C57Bl/6J mice with selective IκB kinase inhibitor IMD-0354 (8mg/kg bw) substantially suppressed COX2 induction in renal medulla, and also significantly reduced urinary PGE2. These data therefore suggest that renal medullary interstitial cell NFκB plays an important role in mediating renal medullary COX2 expression and promoting renal PGE2 synthesis in response to increased dietary sodium. PMID:23900806

  11. Immunohistochemical expression of COX-2, mPGES and EP2 receptor in normal and reactive canine bone and in canine osteosarcoma.

    PubMed

    Millanta, F; Asproni, P; Cancedda, S; Vignoli, M; Bacci, B; Poli, A

    2012-01-01

    Accumulating evidence suggests that cyclooxygenase (COX)-2 is involved in the pathogenesis of human and canine osteosarcoma. The aim of this study was to investigate the expression of COX-2 in normal, reactive and neoplastic canine bone and the events downstream to COX-2 that lead to prostaglandin E(2) (PGE(2)) production. COX-2, microsomal PGE(2) synthase-1 (mPGES-1) and the PGE(2) receptor (EP2) were assessed by immunohistochemistry in 12 samples of normal bone, 14 cases of fracture callus and 27 appendicular osteosarcomas. No immunoreactivity to COX-2, mPGES-1 or EP2 receptor was observed in normal bone. Fifty percent of reactive bone samples expressed COX-2 and 57% expressed mPGES-1 and EP2 receptor, although with weak labelling intensity. Ninety-three percent of osteosarcomas expressed COX-2, while mPGES-1 was expressed by 85% and EP2 receptor by 89% of the tumours. The data confirm that COX-2 is expressed at high level in osteosarcoma and support the use of COX-2 inhibitors to improve the response to chemotherapy. The possibility of blocking the EP2 or the selective inhibition of mPGES-1, rather than COX-2 activity, might decrease the incidence of adverse effects that occur due to the inhibition of prostanoids other than PGE(2).

  12. Lactobacillus casei reduces the inflammatory joint damage associated with collagen-induced arthritis (CIA) by reducing the pro-inflammatory cytokines: Lactobacillus casei: COX-2 inhibitor.

    PubMed

    Amdekar, Sarika; Singh, Vinod; Singh, Rambir; Sharma, Poonam; Keshav, Poonam; Kumar, Avnish

    2011-04-01

    This study evaluated the therapeutic efficacy of Lactobacillus casei in treating rheumatoid arthritis using collagen-induced arthritis (CIA) animal model. Healthy female Wistar rats (weight-180-200 g) were included in this study. Oral administration of L. casei was started on the same day. Indomethacin was used as standard reference drug. Serum level of IL-6, α-TNF, and IL-10 were observed. Four-point arthritis indexes were also assessed at the end of week for 28th day. L. casei-treated rats had shown normal histopathology without any synovial infiltration, pannus formation, cartilage, and bone destruction. Arthritis score was also lower for the group treated with L. casei. Oral administration of L. casei significantly decreased the pro-inflammatory cytokines. Present study suggests that L. casei has potent antiarthritic effect in CIA model. Inhibition of COX-2 via inhibiting the pro-inflammatory cytokines is an understanding of the complex interactions involved in these pathways.

  13. Expression of cyclooxygenase-2 (COX-2) in pituitary tumours

    PubMed Central

    Sokołowski, Grzegorz; Bałdys-Waligórska, Agata; Trofimiuk, Małgorzata; Adamek, Dariusz; Hubalewska-Dydejczyk, Alicja; Gołkowski, Filip

    2012-01-01

    Summary Background Microvessel density in angiogenesis is regarded as a prognostic factor of tumour invasiveness, independent of cell proliferation. In recent studies of pituitary tumours, correlation between the expression of cyclooxygenase-2 (COX-2) and micro-vascularization density and microvessel surface density has been established. We studied the expression of COX-2 in different types of pituitary adenomas to determine the usefulness of COX-2 expression as a prognostic factor of tumour progression or recurrence in patients with hypophyseal tumours. Material/Methods We retrospectively studied a group of 60 patients of mean age 46.7±17.6 (range, 18 to 85) years who underwent pituitary tumour surgery. Expression of COX-2, as determined by immunohistochemistry, was analyzed in relation to histopathology features of tumour, clinical symptoms, MR imaging and post-operative recurrence/progression of disease. Results COX-2 was expressed in adenomas of 87% of patients, with a median index value of 57.5% [IQR=60.5]. Highest COX-2 expression was observed in hormonally inactive adenomas and gonadotropinomas and lowest in prolactinomas. We found no differences in COX-2 expression with respect to patient age, gender, tumour size, degree of tumour invasiveness, or whether tumours were immunopositive or immunonegative for pituitary hormones, nor have we found any relation between COX-2 expression and recurrence or progression of tumour size. Conclusions COX-2 does not appear to be a predictive factor for recurrence or progression of tumour size. Nevertheless, due to the observed relatively high expression of COX-2 in pituitary adenomas, further studies with COX-2 inhibitors are justified in these tumours. PMID:22460097

  14. IL1{beta}-mediated Stromal COX-2 signaling mediates proliferation and invasiveness of colonic epithelial cancer cells

    SciTech Connect

    Zhu, Yingting; Zhu, Min; Lance, Peter

    2012-11-15

    COX-2 is a major inflammatory mediator implicated in colorectal inflammation and cancer. However, the exact origin and role of COX-2 on colorectal inflammation and carcinogenesis are still not well defined. Recently, we reported that COX-2 and iNOS signalings interact in colonic CCD18Co fibroblasts. In this article, we investigated whether activation of COX-2 signaling by IL1{beta} in primary colonic fibroblasts obtained from normal and cancer patients play a critical role in regulation of proliferation and invasiveness of human colonic epithelial cancer cells. Our results demonstrated that COX-2 level was significantly higher in cancer associated fibroblasts than that in normal fibroblasts with or without stimulation of IL-1{beta}, a powerful stimulator of COX-2. Using in vitro assays for estimating proliferative and invasive potential, we discovered that the proliferation and invasiveness of the epithelial cancer cells were much greater when the cells were co-cultured with cancer associated fibroblasts than with normal fibroblasts, with or without stimulation of IL1{beta}. Further analysis indicated that the major COX-2 product, prostaglandin E{sub 2}, directly enhanced proliferation and invasiveness of the epithelial cancer cells in the absence of fibroblasts. Moreover, a selective COX-2 inhibitor, NS-398, blocked the proliferative and invasive effect of both normal and cancer associate fibroblasts on the epithelial cancer cells, with or without stimulation of IL-1{beta}. Those results indicate that activation of COX-2 signaling in the fibroblasts plays a major role in promoting proliferation and invasiveness of the epithelial cancer cells. In this process, PKC is involved in the activation of COX-2 signaling induced by IL-1{beta} in the fibroblasts.

  15. Physiological COX-2 expression in breast epithelium associates with COX-2 levels in ductal carcinoma in situ and invasive breast cancer in young women.

    PubMed

    Fornetti, Jaime; Jindal, Sonali; Middleton, Kara A; Borges, Virginia F; Schedin, Pepper

    2014-04-01

    Cyclooxygenase-2 (COX-2) overexpression is implicated in increased risk and poorer outcomes in breast cancer in young women. We investigated COX-2 regulation in normal premenopausal breast tissue and its relationship to malignancy in young women. Quantitative COX-2 immunohistochemistry was performed on adjacent normal and breast cancer tissues from 96 premenopausal women with known clinical reproductive histories, and on rat mammary glands with distinct ovarian hormone exposures. COX-2 expression in the normal breast epithelium varied more than 40-fold between women and was associated with COX-2 expression levels in ductal carcinoma in situ and invasive cancer. Normal breast COX-2 expression was independent of known breast cancer prognostic indicators, including tumor stage and clinical subtype, indicating that factors regulating physiological COX-2 expression may be the primary drivers of COX-2 expression in breast cancer. Ovarian hormones, particularly at pregnancy levels, were identified as modulators of COX-2 in normal mammary epithelium. However, serial breast biopsy analysis in nonpregnant premenopausal women suggested relatively stable baseline levels of COX-2 expression, which persisted independent of menstrual cycling. These data provide impetus to investigate how baseline COX-2 expression is regulated in premenopausal breast tissue because COX-2 levels in normal breast epithelium may prove to be an indicator of breast cancer risk in young women, and predict the chemopreventive and therapeutic efficacy of COX-2 inhibitors in this population.

  16. Mechanisms by Which 17β-Estradiol (E2) Suppress Neuronal cox-2 Gene Expression

    PubMed Central

    Stacey, Winfred; Bhave, Shreyas; Uht, Rosalie M.

    2016-01-01

    E2 attenuates inflammatory responses by suppressing expression of pro-inflammatory genes. Given that inflammation is increasingly being associated with neurodegenerative and psychiatric processes, we sought to elucidate mechanisms by which E2 down-regulates a component of an inflammatory response, cyclooxygenase– 2 (COX-2) expression. Although inflammatory processes in the brain are usually associated with microglia and astrocytes, we found that the COX-2 gene (cox-2) was expressed in a neuronal context, specifically in an amygdalar cell line (AR-5). Given that COX-2 has been reported to be in neurons in the brain, and that the amygdala is a site involved in neurodegenerative and neuropsychiatric processes, we investigated mechanisms by which E2 could down-regulate cox-2 expression in the AR-5 line. These cells express estrogen receptors alpha (ERα) and beta (ERβ), and as shown here cox-2. At the level of RNA, E2 and the ERβ selective ligand diarylpropionitrile (DPN) both attenuated gene expression, whereas the ERα selective ligand propyl pyrazole triol (PPT) had no effect. Neither ligand increased ERβ at the cox-2 promoter. Rather, DPN decreased promoter occupancy of NF-κB p65 and histone 4 (H4) acetylation. Treatment with the non-specific HDAC inhibitor Trichostatin A (TSA) counteracted DPN’s repressive effects on cox-2 expression. In keeping with the TSA effect, E2 and DPN increased histone deacetylase one (HDAC1) and switch-independent 3A (Sin3A) promoter occupancy. Lastly, even though E2 increased CpG methylation, DPN did not. Taken together, the pharmacological data indicate that ERβ contributes to neuronal cox-2 expression, as measured by RNA levels. Furthermore, ER ligands lead to increased recruitment of HDAC1, Sin3A and a concomitant reduction of p65 occupancy and Ac-H4 levels. None of the events, however, are associated with a significant recruitment of ERβ at the promoter. Thus, ERβ directs recruitment to the cox-2 promoter, but does so in

  17. Immunomodulatory drug CC-4047 is a cell-type and stimulus-selective transcriptional inhibitor of cyclooxygenase 2.

    PubMed

    Ferguson, Gregory D; Jensen-Pergakes, Kristen; Wilkey, Candice; Jhaveri, Urvi; Richard, Normand; Verhelle, Dominique; De Parseval, Laure Moutouh; Corral, Laura G; Xie, Weilin; Morris, Christopher L; Brady, Helen; Chan, Kyle

    2007-03-01

    COX2 (prostaglandin G/H synthase, PTGS2) is a well-validated target in the fields of both oncology and inflammation. Despite their significant toxicity profile, non-steroidal anti-inflammatory drugs (NSAIDs) have become standard of care in the treatment of many COX2-mediated inflammatory conditions. In this report, we show that one IMiDs((R)) immunomodulatory drug, CC-4047, can reduce the levels of COX2 and the production of prostaglandins (PG) in human LPS-stimulated monocytes. The inhibition of COX2 by CC-4047 occurs at the level of gene transcription, by reducing the LPS-stimulated transcriptional activity at the COX2 gene. Because it is a transcriptional rather than an enzymatic inhibitor of COX2, CC-4047 inhibition of PG production is not susceptible to competition by exogenous arachadonic acid (AA). The distinct mechanisms of action allow CC-4047 and a COX2-selective NSAID to work additively to block PG secretion from monocytes. CC-4047 does not, however, block COX2 induction in or prostacyclin secretion from IL-1beta stimulated human umbilical vein endothelial cells (HUVEC) cells, nor does it inhibit COX1 in either monocytes or HUVEC cells. CC-4047 also inhibits COX2 and PG production in monocytes derived from patients with sickle cell disease (SCD). Taken together, the data in this manuscript suggest CC-4047 will provide important anti-inflammatory benefit to patients and will improve the safety of NSAIDs in the treatment of SCD or other inflammatory conditions.

  18. Involvement of COX2-Thromboxane Pathway in TCDD-Induced Precardiac Edema in Developing Zebrafish

    PubMed Central

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

    2015-01-01

    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 cancelled 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. PMID:24858302

  19. Selective cyclooxygenase-2 inhibitor use and progression of renal function in patients with chronic kidney disease: a single-center retrospective cohort study

    PubMed Central

    Kaewput, Wisit; Disorn, Preedee; Satirapoj, Bancha

    2016-01-01

    Background The use of selective COX-2 (sCOX-2) inhibitors with acute kidney injury, salt water retention, and cardiovascular events have been correlated in subjects with normal kidney function, but sCOX-2 inhibitor use concerning the progression of chronic kidney disease (CKD) remains uncertain. Objectives To determine the progression of renal function and electrolyte abnormalities among CKD patients after using sCOX-2 inhibitors during short- and long-term periods. Methods The study employed a retrospective cohort design comprising all types of CKD patients with and without sCOX-2 inhibitors (celecoxib and etoricoxib). Data collected included medical data, estimated glomerular filtration rate (eGFR), and serum electrolytes at 3 and 6 months between January 2009 and January 2014. Subjects attended the outpatient clinic and were then followed up until discontinuation of the drugs at years 1 and 2 until May 2016. Results Ninety-two CKD patients on sCOX-2 inhibitors and 92 CKD patients without sCOX-2 inhibitors were included. The sCOX-2 inhibitor group showed more decline in eGFR than the control group at 3 and 6 months of follow-up (–8.27±9.75 vs –1.64±6.05 mL/min/1.73 m2, P<0.001 and –12.36±6.48 vs –4.31±5.11 mL/min/1.73 m2, P=0.001, respectively) and at 1 and 2 years of follow-up after subjects discontinued sCOX-2 (–6.84±10.34 vs –1.61±8.93 mL/min/1.73 m2, P=0.004 and –10.26±10.19 vs –5.12±8.61 mL/min/1.73 m2, P=0.005, respectively). In addition, the sCOX-2 inhibitor group had significantly more increased serum potassium during the study follow-up than the control group. Conclusion The sCOX-2 inhibitors are associated with an increased risk for rapid eGFR decline and hyperkalemia in both the short term and in the long term after sCOX-2 inhibitors were terminated in the setting of a community-based CKD population. For CKD patients, these results suggest that sCOX-2 inhibitors should be closely monitored and chronic exposure to any sCOX-2

  20. Design, Synthesis and Biological Evaluation of New 1, 4-Dihydropyridine (DHP) Derivatives as Selective Cyclooxygenase-2 Inhibitors.

    PubMed

    Sabakhi, Iman; Topuzyan, Vigen; Hajimahdi, Zahra; Daraei, Bahram; Arefi, Hadi; Zarghi, Afshin

    2015-01-01

    As a continuous research for discovery of new COX-2 inhibitors, chemical synthesis, in vitro biological activity and molecular docking study of a new group of 1, 4-dihydropyridine (DHP) derivatives were presented. Novel synthesized compounds possessing a COX-2 SO2Me pharmacophore at the para position of C-4 phenyl ring, different hydrophobic groups (R1) at C-2 position and alkoxycarbonyl groups (COOR2) at C-3 position of 1, 4-dihydropyridine, displayed selective inhibitory activity against COX-2 isozyme. Among them, compound 5e was identified as the most potent and selective COX-2 inhibitor with IC50 value of 0.30 μM and COX-2 selectivity index of 92. Molecular docking study was performed to determine probable binding models of compound 5e. The study showed that the p-SO2Me-phenyl fragment of 5e inserted inside secondary COX-2 binding site (Arg(513), Phe(518), Gly(519), and His(90)). The structure-activity relationships acquired reveal that compound 5e with methyl and ethoxycarbonyl as R1 and COOR2 substitutions has the necessary geometry to provide selective inhibition of the COX-2 isozyme and it can be a good basis for the development of new hits.

  1. The role of chemoprevention by selective cyclooxygenase-2 inhibitors in colorectal cancer patients - a population-based study

    PubMed Central

    2012-01-01

    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. PMID:23217168

  2. COX-1 vs. COX-2 as a determinant of basal tone in the internal anal sphincter

    PubMed Central

    de Godoy, Márcio A. F.; Rattan, Neeru; Rattan, Satish

    2009-01-01

    Prostanoids, produced endogenously via cyclooxygenases (COXs), have been implicated in the sustained contraction of different smooth muscles. The two major types of COXs are COX-1 and COX-2. The COX subtype involved in the basal state of the internal anal sphincter (IAS) smooth muscle tone is not known. To identify the COX subtype, we examined the effect of COX-1- and COX-2-selective inhibitors, SC-560 and rofecoxib, respectively, on basal tone in the rat IAS. We also determined the effect of selective deletion of COX-1 and COX-2 genes (COX-1−/− and COX-2−/− mice) on basal tone in murine IAS. Our data show that SC-560 causes significantly more efficacious and potent concentration-dependent decreases in IAS tone than rofecoxib. In support of these data, significantly higher levels of COX-1 than COX-2 mRNA were found in the IAS. In addition, higher levels of COX-1 mRNA and protein were expressed in rat IAS than rectal smooth muscle. In wild-type mice, IAS tone was decreased 41.4 ± 3.4% (mean ± SE) by SC-560 (1 × 10−5 M) and 5.4 ± 2.2% by rofecoxib (P < 0.05, n = 5). Basal tone was 0.172 ± 0.021 mN//mg in the IAS from wild-type mice and significantly less (0.080 ± 0.015 mN/mg) in the IAS from COX-1−/− mice (P < 0.05, n = 5). However, basal tone in COX-2−/− mice was not significantly different from that in wild-type mice. We conclude that COX-1-related products contribute significantly to IAS tone. PMID:19056763

  3. COX-1 and COX-2 inhibition in horse blood by phenylbutazone, flunixin, carprofen and meloxicam: an in vitro analysis.

    PubMed

    Beretta, C; Garavaglia, G; Cavalli, M

    2005-10-01

    We report on the inhibitory activity of the NSAIDs meloxicam, carprofen, phenylbutazone and flunixin, on blood cyclooxygenases in the horse using in vitro enzyme-linked assays. As expected, comparison of IC50 indicated that meloxicam and carprofen are more selective inhibitors of COX-2 than phenylbutazone and flunixin; meloxicam was the most advantageous for horses of four NSAIDs examined. However at IC80, phenylbutazone (+134.4%) and flunixin (+29.7%) had greater COX-2 selectivity than at IC50, and meloxicam (-41.2%) and carprofen (-12.9%) had lower COX-2 selectivity than at IC50. We therefore propose that the selectivity of NSAIDs should be assessed at the 80% as well as 50% inhibition level.

  4. Improved Antitumor Activity of a Therapeutic Melanoma Vaccine through the Use of the Dual COX-2/5-LO Inhibitor Licofelone

    PubMed Central

    Neumann, Silke; Shirley, Simon A.; Kemp, Roslyn A.; Hook, Sarah M.

    2016-01-01

    Immune-suppressive cell populations impair antitumor immunity and can contribute to the failure of immune therapeutic approaches. We hypothesized that the non-steroidal anti-inflammatory drug licofelone, a dual cyclooxygenase-2/5-LO inhibitor, would improve therapeutic melanoma vaccination by reducing immune-suppressive cell populations. Therefore, licofelone was administered after tumor implantation, either alone or in combination with a peptide vaccine containing a long tyrosinase-related protein 2-peptide and the adjuvant α-galactosylceramide, all formulated into cationic liposomes. Mice immunized with the long-peptide vaccine and licofelone showed delayed tumor growth compared to mice given the vaccine alone. This protection was associated with a lower frequency of immature myeloid cells (IMCs) in the bone marrow (BM) and spleen of tumor-inoculated mice. When investigating the effect of licofelone on IMCs in vitro, we found that the prostaglandin E2-induced generation of IMCs was decreased in the presence of licofelone. Furthermore, pre-incubation of BM cells differentiated under IMC-inducing conditions with licofelone reduced the secretion of cytokines interleukin (IL)-10 and -6 upon lipopolysaccharides (LPS) stimulation as compared to untreated cells. Interestingly, licofelone increased IL-6 and IL-10 secretion when administered after the LPS stimulus, demonstrating an environment-dependent effect of licofelone. Our findings support the use of licofelone to reduce tumor-promoting cell populations. PMID:27994586

  5. siRNA-mediated knock-down of COX-2 in melanocytes suppresses melanogenesis.

    PubMed

    Kim, Ji Y; Shin, Jae Y; Kim, Miri R; Hann, Seung-Kyung; Oh, Sang H

    2012-06-01

    Cyclooxygenase-2 (COX-2) is an enzyme induced in response to multiple mitogenic and inflammatory stimuli, including UV light. UV-induced COX-2 expression induces production of prostaglandin E2 (PGE2) in keratinocytes, which mediates inflammation and cell proliferation. Until recently, studies regarding COX-2 and PGE2 in the skin have focused on keratinocytes and skin cancer and the effect of PGs produced by keratinocytes on melanocytes. However, the effects of COX-2 itself or COX-2 inhibitors on melanogenesis are not well known. Therefore, to establish the role of COX-2 in melanogenesis, we investigated the effects of knock-down of COX-2 in melanocytes on melanin production and the expression of melanogenic molecules through silencing of COX-2 expression with COX-2 short interfering RNA (siRNA). COX-2 knock-down in melanocytes decreased the expressions of tyrosinase, TRP-1, TRP-2, gp100 and MITF and also reduced tyrosinase enzyme activity. Furthermore, COX-2 siRNA-transfected melanocytes showed markedly reduced alpha-melanocyte stimulating hormone (α-MSH)-induced melanin production. In addition, α-MSH-induced COX-2 expression in both scrambled siRNA-transfected and COX-2 siRNA-transfected melanocytes was greater than α-MSH-untreated cells. Our results suggest that COX-2 might be a candidate target for the development of anti-melanogenic agents and α-MSH-induced pigmentation could be closely associated with COX-2 expression. COX-2 inhibitors might therefore be of particular use in whitening cosmetics for hyperpigmentation disorders such as melasma, postinflammatory hyperpigmentation and solar lentigo.

  6. Inhibition of cyclooxygenase (COX)-2 affects endothelial progenitor cell proliferation

    SciTech Connect

    Colleselli, Daniela; Bijuklic, Klaudija; Mosheimer, Birgit A.; Kaehler, Christian M. . E-mail: C.M.Kaehler@uibk.ac.at

    2006-09-10

    Growing evidence indicates that inducible cyclooxygenase-2 (COX-2) is involved in the pathogenesis of inflammatory disorders and various types of cancer. Endothelial progenitor cells recruited from the bone marrow have been shown to be involved in the formation of new vessels in malignancies and discussed for being a key point in tumour progression and metastasis. However, until now, nothing is known about an interaction between COX and endothelial progenitor cells (EPC). Expression of COX-1 and COX-2 was detected by semiquantitative RT-PCR and Western blot. Proliferation kinetics, cell cycle distribution and rate of apoptosis were analysed by MTT test and FACS analysis. Further analyses revealed an implication of Akt phosphorylation and caspase-3 activation. Both COX-1 and COX-2 expression can be found in bone-marrow-derived endothelial progenitor cells in vitro. COX-2 inhibition leads to a significant reduction in proliferation of endothelial progenitor cells by an increase in apoptosis and cell cycle arrest. COX-2 inhibition leads further to an increased cleavage of caspase-3 protein and inversely to inhibition of Akt activation. Highly proliferating endothelial progenitor cells can be targeted by selective COX-2 inhibition in vitro. These results indicate that upcoming therapy strategies in cancer patients targeting COX-2 may be effective in inhibiting tumour vasculogenesis as well as angiogenic processes.

  7. Palbociclib inhibits epithelial-mesenchymal transition and metastasis in breast cancer via c-Jun/COX-2 signaling pathway.

    PubMed

    Qin, Ge; Xu, Fei; Qin, Tao; Zheng, Qiufan; Shi, Dingbo; Xia, Wen; Tian, Yun; Tang, Yanlai; Wang, Jingshu; Xiao, Xiangshen; Deng, Wuguo; Wang, Shusen

    2015-12-08

    Palbociclib, a highly selective CDK4/6 inhibitor, has been shown to be a novel anti-tumor agent that suppresses breast cancer cell proliferation. However, its anti-metastasis activity remains controversial. In the present study, we evaluated whether palbociclib prevented breast cancer cell metastasis and revealed its regulatory mechanism. We found that palbociclib inhibited migration and invasion in the breast cancer cells MDA-MB-231 and T47D. The epithelial-mesenchymal transition (EMT) markers, vimentin and Snail, were down-regulated with palbociclib treatment. Moreover, we revealed that this inhibition was mediated by the c-Jun/COX-2 pathway. COX-2 was decreased after palbociclib treatment. The production of PGE2 was also reduced along with COX-2. Additionally, our data showed that c-Jun, a crucial transcriptional regulator of COX-2, was down-regulated by palbociclib. We found that palbociclib weakened the COX-2 promoter binding activity of c-Jun and prevented its translocation from the cytoplasm to cell nuclei. Bioluminescence imaging and tail intravenous injection were used to evaluate the anti-metastasis effect of palbociclib in vivo. The data demonstrated that palbociclib reduced breast cancer metastasis to the lung. These results therefore demonstrated that the anti-metastasis activity of palbociclib is mediated via the c-Jun/COX-2 signaling pathway by inhibiting EMT in breast cancer cells.

  8. Palbociclib inhibits epithelial-mesenchymal transition and metastasis in breast cancer via c-Jun/COX-2 signaling pathway

    PubMed Central

    Zheng, Qiufan; Shi, Dingbo; Xia, Wen; Tian, Yun; Tang, Yanlai; Wang, Jingshu; Xiao, Xiangshen; Deng, Wuguo; Wang, Shusen

    2015-01-01

    Palbociclib, a highly selective CDK4/6 inhibitor, has been shown to be a novel anti-tumor agent that suppresses breast cancer cell proliferation. However, its anti-metastasis activity remains controversial. In the present study, we evaluated whether palbociclib prevented breast cancer cell metastasis and revealed its regulatory mechanism. We found that palbociclib inhibited migration and invasion in the breast cancer cells MDA-MB-231 and T47D. The epithelial-mesenchymal transition (EMT) markers, vimentin and Snail, were down-regulated with palbociclib treatment. Moreover, we revealed that this inhibition was mediated by the c-Jun/COX-2 pathway. COX-2 was decreased after palbociclib treatment. The production of PGE2 was also reduced along with COX-2. Additionally, our data showed that c-Jun, a crucial transcriptional regulator of COX-2, was down-regulated by palbociclib. We found that palbociclib weakened the COX-2 promoter binding activity of c-Jun and prevented its translocation from the cytoplasm to cell nuclei. Bioluminescence imaging and tail intravenous injection were used to evaluate the anti-metastasis effect of palbociclib in vivo. The data demonstrated that palbociclib reduced breast cancer metastasis to the lung. These results therefore demonstrated that the anti-metastasis activity of palbociclib is mediated via the c-Jun/COX-2 signaling pathway by inhibiting EMT in breast cancer cells. PMID:26540629

  9. Molecular Dynamics Simulations of Arachidonic Acid Complexes with COX-1 and COX-2

    PubMed Central

    Furse, Kristina E.; Pratt, Derek A.; Porter, Ned A.; Lybrand, Terry P.

    2008-01-01

    The cyclooxygenase (COX) enzymes are responsible for the committed step in prostaglandin biosynthesis, the generation of prostaglandin H2. As a result, these enzymes are pharmacologically important targets for non-steroidal anti-inflammatory drugs, such as aspirin and newer COX-2 selective inhibitors. The cyclooxygenases are functional homodimers, and each subunit contains both a cyclooxygenase and a peroxidase active site. These enzymes are quite interesting mechanistically, as the conversion of arachidonic acid to prostaglandin H2 requires two oxygenation and two cyclization reactions, resulting in the formation of five new chiral centers with nearly absolute regio- and stereochemical fidelity. We have used molecular dynamics (MD) simulations to investigate the equilibrium behavior of both COX-1 and COX-2 enzyme isoforms with bound arachidonate. These simulations were compared with reference simulations of arachidonate in solution to explore the effect of enzyme on substrate conformation and positioning in the active site. The simulations suggest that the substrate has greater conformational freedom in the COX-2 active site, consistent with the larger COX-2 active site volume observed in X-ray crystal structures. The simulations reveal different conformational behavior for arachidonate in each subunit over the course of extended equilibrium MD simulations. The simulations also provide detailed information for several protein channels that might be important for oxygen and water transport to or from active sites, or for intermediate trafficking between the cyclooxygenase and peroxidase active sites. The detailed comparisons for COX-1 versus COX-2 active site structural fluctuations may also provide useful information for design of new isozyme-selective inhibitors. PMID:16519514

  10. Novel determination of nabumetone, a cox-2 inhibitor precursor via its 4-carboxyl-2,6-dinitrobenzene diazonium (CDNBD) derived AZO dye.

    PubMed

    Adegoke, A O; Idowu, S O; Olaniyi, A A

    2007-09-01

    A novel colorimetric determination ofnabumetone in tablets has been developed. The assay is based on chemical derivatization (aromatic ring derivatization technique) using newly developed 4-carboxyl-2,6-dinitrobenzene diazonium (CDNBD) ion as the chromogenic derivatizing reagent and resultant formation of azo dye.Optimization studies established an optimal reaction time of 10 minutes at 30 degrees C after mixing the drug/reagent mixture in a vortex mixer for 10 sec. A new absorption maximum (ë(max)) was found at 470 nm, which was selected as analytical wavelength. The assays were linear over 1-6 microg/ml of nabumetone and the optimal reaction required a 2:1 reagent/drug stoichiometric ratio. The developed method has a low limit of detection of 0.39 microg/ml, and is reproducible (1.81% RSD). It has been applied successfully to the assay of nabumetone tablets and is of equivalent accuracy (p > 0.05) with the official (B.P) HPLC method. The new method is simple, has the main advantage of employing a more affordable instrumentation and could find application in routine in-process quality control of nabumetone tablets.

  11. Hypoxia promotes 786-O cells invasiveness and resistance to sorafenib via HIF-2α/COX-2.

    PubMed

    Zhao, Chun-Xiong; Luo, Chun-Li; Wu, Xiao-Hou

    2015-01-01

    Accumulating evidences indicated that hypoxia-induced factors and COX-2 play a important role in tumorigenesis in various human cancer. Yet, the relationship between HIFs and COX-2 in human renal cancer remains unclear. The present study was to examine the role of HIFs and COX-2 in the invasiveness and the resistance to target agent in renal cancer cell line (786-O). In 786-O cells, hypoxia induced the increase in the protein expression of HIF1 and HIF2. We also demonstrate that hypoxia up-regulated the protein expression of COX-2 and Snail, but down-regulation of E-cadherin expression in 786-O cells promoted the invasiveness of 786-O cells and enhanced the resistance of 786-O cells to sorafenib. siRNA target to HIF1α, HIF2α and NS398, a selective inhibitor of COX-2, were used in this study. Only siRNA-HIF2α significantly suppressed the protein expression of HIF2 and COX-2, then decreased the invasive ability and resistance of 786-O cells to sorafenib under hypoxia. NS398 attenuated the increase in invasive cells number and the IC50 value of sorafenib induced by hypoxia. In conclusion, our results demonstrated that hypoxia promoted the invasiveness and resistance of 786-O cells to sorafenib via HIF2 and COX-2 and induced the activation of Snail/E-cadherin, suggesting that a signalling mechanism involving HIF2/COX2 modulates invasiveness and resistance to sorafenib in 786-O cells under hypoxia.

  12. Prevention of upper aerodigestive tract cancer in zinc-deficient rodents: inefficacy of genetic or pharmacological disruption of COX-2.

    PubMed

    Fong, Louise Y Y; Jiang, Yubao; Riley, Maurisa; Liu, Xianglan; Smalley, Karl J; Guttridge, Denis C; Farber, John L

    2008-03-01

    Zinc deficiency in humans is associated with an increased risk of upper aerodigestive tract (UADT) cancer. In rodents, zinc deficiency predisposes to carcinogenesis by causing proliferation and alterations in gene expression. We examined whether in zinc-deficient rodents, targeted disruption of the cyclooxygenase (COX)-2 pathway by the COX-2 selective inhibitor celecoxib or by genetic deletion prevent UADT carcinogenesis. Tongue cancer prevention studies were conducted in zinc-deficient rats previously exposed to a tongue carcinogen by celecoxib treatment with or without zinc replenishment, or by zinc replenishment alone. The ability of genetic COX-2 deletion to protect against chemically-induced forestomach tumorigenesis was examined in mice on zinc-deficient versus zinc-sufficient diet. The expression of 3 predictive biomarkers COX-2, nuclear factor (NF)-kappa B p65 and leukotriene A(4) hydrolase (LTA(4)H) was examined by immunohistochemistry. In zinc-deficient rats, celecoxib without zinc replenishment reduced lingual tumor multiplicity but not progression to malignancy. Celecoxib with zinc replenishment or zinc replenishment alone significantly lowered lingual squamous cell carcinoma incidence, as well as tumor multiplicity. Celecoxib alone reduced overexpression of the 3 biomarkers in tumors slightly, compared with intervention with zinc replenishment. Instead of being protected, zinc-deficient COX-2 null mice developed significantly greater tumor multiplicity and forestomach carcinoma incidence than wild-type controls. Additionally, zinc-deficient COX-2-/- forestomachs displayed strong LTA(4)H immunostaining, indicating activation of an alternative pathway under zinc deficiency when the COX-2 pathway is blocked. Thus, targeting only the COX-2 pathway in zinc-deficient animals did not prevent UADT carcinogenesis. Our data suggest zinc supplementation should be more thoroughly explored in human prevention clinical trials for UADT cancer.

  13. Isomeric methoxy analogs of nimesulide for development of brain cyclooxygense-2 (COX-2)-targeted imaging agents: Synthesis, in vitro COX-2-inhibitory potency, and cellular transport properties.

    PubMed

    Yamamoto, Yumi; Hisa, Takuya; Arai, Jun; Saito, Yohei; Yamamoto, Fumihiko; Mukai, Takahiro; Ohshima, Takashi; Maeda, Minoru; Ohkubo, Yasuhito

    2015-11-01

    Nimesulide analogs bearing a methoxy substituent either at the ortho-, meta- or para-position on the phenyl ring, were designed, synthesized, and evaluated for potential as radioligands for brain cyclooxygenase-2 (COX-2) imaging. The synthesis of nimesulide and regioisomeric methoxy analogs was based on the copper-mediated arylation of phenolic derivatives for the construction of diaryl ethers. These isomeric methoxy analogs displayed lipophilicity similar to that of nimesulide itself, as evidenced by their HPLC logP7.4 values. In vitro inhibition studies using a colorimetric COX (ovine) inhibitor-screening assay demonstrated that the para-methoxy substituted analog retains the inhibition ability and selectivity observed for parent nimesulide toward COX-2 enzyme, whereas the meta- and ortho-methoxy substituents detrimentally affected COX-2-inhibition activity, which was further supported by molecular docking studies. Bidirectional transport cellular studies using Caco-2 cell culture model in the presence of the P-glycoprotein (P-gp) inhibitor, verapamil, showed that P-gp did not have a significant effect on the efflux of the para-methoxy substituted analog. Further investigations using the radiolabeled form of the para-methoxy substituted analog is warranted for in vivo characterization.

  14. Preferential and non-selective cyclooxygenase inhibitors reduce inflammation during lipopolysaccharide-induced synovitis.

    PubMed

    Morton, Alison J; Campbell, Nigel B; Gayle, J'mai M; Redding, W Rich; Blikslager, Anthony T

    2005-04-01

    Synovitis in horses is frequently treated by administration of non-steroidal anti-inflammatory drugs (NSAIDs), which inhibit cyclooxygenase isoforms (COX-1 and COX-2). Constitutively expressed COX-1 is involved in physiologic functions such as maintenance of gastric mucosal integrity, whereas COX-2 is up-regulated at sites of inflammation. Thus, COX-2 inhibitors reduce inflammation with reduced gastrointestinal side effects as compared to non-selective COX inhibitors. The objective of the present study was to compare the anti-inflammatory effects of the preferential COX-2 inhibitor etodolac with the non-selective COX inhibitor phenylbutazone in horses with lipopolysaccharide (LPS)-induced synovitis. Three groups of horses (n=6) received no treatment, phenylbutazone (4.4 mg/kg, IV, q12h), or etodolac (23 mg/kg, IV, q12h), respectively, 2-h following injection of LPS into one middle carpal joint. Synovial fluid was analyzed for white blood cell (WBC) count, and TXB2 and PGE2 levels. Phenylbutazone and etodolac significantly reduced WBC count 6 and 24-h following injection of LPS compared to untreated horses. In addition, both drugs significantly reduced PGE2 levels (P<0.05) 6-h following LPS injection, whereas the probable COX-1 prostanoid TXB2 was significantly reduced by phenylbutazone (P<0.05), but not etodolac. Etodolac may serve as a more selective anti-inflammatory agent than phenylbutazone for treatment of equine synovitis.

  15. Use of Selective Cyclooxygenase-2 Inhibitors, Other Analgesics, and Risk of Glioma

    PubMed Central

    Seliger, Corinna; Meier, Christoph R.; Becker, Claudia; Jick, Susan S.; Bogdahn, Ulrich; Hau, Peter; Leitzmann, Michael F.

    2016-01-01

    Background Selective cyclooxygenase-2 (COX-2) inhibitors are analgesic, antipyretic, and anti-inflammatory drugs. They have been found to inhibit the development of glioma in laboratory investigations. Whether these drugs reduce the risk of glioma incidence in humans is unknown. Methods We conducted a matched case-control analysis using the U.K.-based Clinical Practice Research Datalink (CPRD). We identified 2,469 cases matched to 24,690 controls on age, sex, calendar time, general practice, and number of years of active history in the CPRD prior to the index date. We conducted conditional logistic regression analyses to determine relative risks, estimated as odds ratios (ORs) with 95% confidence intervals (CIs) of glioma in relation to use of selective COX-2 inhibitors, adjusted for several confounding variables. Results Use of selective COX-2 inhibitors was unrelated to risk of glioma (adjusted OR for 1–9 versus 0 prescriptions = 1.02; 95% CI = 0.92–1.13, 10–29 versus 0 prescriptions = 1.01; 95% CI = 0.80–1.28, ≥30 versus 0 prescriptions = 1.16; 95% CI = 0.86–1.55). Trends for increasing numbers of prescriptions for other non-steroidal anti-inflammatory drugs (NSAIDs), and non-NSAID analgesics were also not associated with glioma risk. Conclusion Further epidemiologic studies are needed to confirm the null relation of use of selective COX-2 inhibitors to glioma risk and to explain the discrepancy between laboratory investigations and our observational study. Impact: Use of selective COX-2 inhibitors is unrelated to glioma risk. PMID:26871579

  16. COX-2 and Prostate Cancer Angiogenesis

    DTIC Science & Technology

    2002-03-01

    sphingomyelin to ceramide , a mediator of apopto- sis (Figure 1).10 The initial interest in COX-2 grew out of the In colon cancer, much of the focus has been...Sphingomyelin - Ceramide Arachidanic Acid \\\\ COX-1 / COX-2 Prostaglandin G2 Prostaglandin H2 Oxidation of Xenobiolics Prostaglandins Malordialdehyde FIGURE 1...variety of tissues in- corneal model, it was demonstrated that endothe- cluding skin , urinary bladder, gastric mucosa, lial cell COX-2 is essential for

  17. HNE as an inducer of COX-2.

    PubMed

    Uchida, Koji

    2017-02-09

    Cyclooxygenase-2 (COX-2), an inducible isoform responsible for high levels of prostaglandin (PG) production during inflammation and immune responses, mediate a variety of biological actions involved in vascular pathophysiology. COX-2 is induced by various stimuli, including proinflammatory cytokines, to result in PG synthesis associated with inflammation and carcinogenesis. 4-Hydroxy-2-nonenal (HNE) is one of a group of small molecules that can induce COX-2 expression. The mechanistic studies have revealed that the HNE-induced COX-2 expression results from the stabilization of COX-2 mRNA mediated by the p38 mitogen-activated protein kinase signaling pathway and uniquely requires a serum component, which is eventually identified to be modified low-density lipoproteins (LDLs), such as the oxidized form of LDLs. It has also been shown that HNE-induced COX-2 expression is mechanistically linked to the expression of transcription factor p53 and that the overexpression of COX-2 is associated with down-regulation of a proteasome subunit, leading to the enhanced accumulation of p53 and ubiquitinated proteins and to the enhanced sensitivity toward HNE. Thus, the overall mechanism and pathophysiological role of the COX-2 induction by HNE have become increasingly evident.

  18. Ku80 cooperates with CBP to promote COX-2 expression and tumor growth

    PubMed Central

    Qin, Yu; Xuan, Yang; Jia, Yunlu; Hu, Wenxian; Yu, Wendan; Dai, Meng; Li, Zhenglin; Yi, Canhui; Zhao, Shilei; Li, Mei; Du, Sha; Cheng, Wei; Xiao, Xiangsheng; Chen, Yiming; Wu, Taihua; Meng, Songshu; Yuan, Yuhui; Liu, Quentin; Huang, Wenlin; Guo, Wei; Wang, Shusen; Deng, Wuguo

    2015-01-01

    Cyclooxygenase-2 (COX-2) plays an important role in lung cancer development and progression. Using streptavidin-agarose pulldown and proteomics assay, we identified and validated Ku80, a dimer of Ku participating in the repair of broken DNA double strands, as a new binding protein of the COX-2 gene promoter. Overexpression of Ku80 up-regulated COX-2 promoter activation and COX-2 expression in lung cancer cells. Silencing of Ku80 by siRNA down-regulated COX-2 expression and inhibited tumor cell growth in vitro and in a xenograft mouse model. Ku80 knockdown suppressed phosphorylation of ERK, resulting in an inactivation of the MAPK pathway. Moreover, CBP, a transcription co-activator, interacted with and acetylated Ku80 to co-regulate the activation of COX-2 promoter. Overexpression of CBP increased Ku80 acetylation, thereby promoting COX-2 expression and cell growth. Suppression of CBP by a CBP-specific inhibitor or siRNA inhibited COX-2 expression as well as tumor cell growth. Tissue microarray immunohistochemical analysis of lung adenocarcinomas revealed a strong positive correlation between levels of Ku80 and COX-2 and clinicopathologic variables. Overexpression of Ku80 was associated with poor prognosis in patients with lung cancers. We conclude that Ku80 promotes COX-2 expression and tumor growth and is a potential therapeutic target in lung cancer. PMID:25797267

  19. Automated docking and molecular dynamics simulations of nimesulide in the cyclooxygenase active site of human prostaglandin-endoperoxide synthase-2 (COX-2)

    NASA Astrophysics Data System (ADS)

    García-Nieto, Raquel; Pérez, Carlos; Gago, Federico

    2000-02-01

    Molecular models of the complex between the selective COX-2 inhibitor nimesulide and the cyclooxygenase active site of human prostaglandin-endoperoxide synthase-2 have been built using a combination of homology modelling, conformational searching and automated docking techniques. The stability of the resulting complexes has been assessed by molecular dynamics simulations and interaction energy decomposition. It is found that nimesulide exploits the extra space made available by the replacement at position 523 of an isoleucine residue in COX-1 by a valine in COX-2 and establishes electrostatic interactions with both Arg-106 and Arg-499 (Arg-120 and Arg-513 in PGHS-1 numbering). Two alternate binding modes are proposed which are compatible with the pharmacological profile of this agent as a COX-2 selective inhibitor.

  20. Inhibition of 11β-Hydroxysteroid Dehydrogenase Type II Suppresses Lung Carcinogenesis by Blocking Tumor COX-2 Expression as Well as the ERK and mTOR Signaling Pathways

    PubMed Central

    Yang, Shilin; Yao, Bing; Zhang, Bixiang; Chen, Xiaoping; Pozzi, Ambra; Zhang, Ming-Zhi

    2015-01-01

    Lung cancer is by far the leading cause of cancer death. Early diagnosis and prevention remain the best approach to reduce the overall morbidity and mortality. Experimental and clinical evidence have shown that cyclooxygenase-2 (COX-2) derived prostaglandin E2 (PGE2) contributes to lung tumorigenesis. COX-2 inhibitors suppress the development and progression of lung cancer. However, increased cardiovascular risks of COX-2 inhibitors limit their use in chemoprevention of lung cancers. Glucocorticoids are endogenous and potent COX-2 inhibitors, and their local actions are down-regulated by 11β–hydroxysteroid dehydrogenase type II (11ßHSD2)-mediated metabolism. We found that 11βHSD2 expression was increased in human lung cancers and experimental lung tumors. Inhibition of 11βHSD2 activity enhanced glucocorticoid-mediated COX-2 inhibition in human lung carcinoma cells. Furthermore, 11βHSD2 inhibition suppressed lung tumor growth and invasion in association with increased tissue active glucocorticoid levels, decreased COX-2 expression, inhibition of ERK and mTOR signaling pathways, increased tumor endoplasmic reticulum stress as well as increased lifespan. Therefore, 11βHSD2 inhibition represents a novel approach for lung cancer chemoprevention and therapy by increasing tumor glucocorticoid activity, which in turn selectively blocks local COX-2 activity and/or inhibits the ERK and mTOR signaling pathways. PMID:26011146

  1. Pioglitazone reduces angiotensin II-induced COX-2 expression through inhibition of ROS production and ET-1 transcription in vascular cells from spontaneously hypertensive rats.

    PubMed

    Pérez-Girón, Jose V; Palacios, Roberto; Martín, Angela; Hernanz, Raquel; Aguado, Andrea; Martínez-Revelles, Sonia; Barrús, María T; Salaices, Mercedes; Alonso, María J

    2014-06-01

    Glitazones have anti-inflammatory properties by interfering with the transcription of proinflammatory genes, such as cyclooxygenase (COX)-2, and with ROS production, which are increased in hypertension. This study analyzed whether pioglitazone modulates COX-2 expression in hypertension by interfering with ROS and endothelin (ET)-1. In vivo, pioglitazone (2.5 mg·kg(-1)·day(-1), 28 days) reduced the greater levels of COX-2, pre-pro-ET-1, and NADPH oxidase (NOX) expression and activity as well as O2 (·-) production found in aortas from spontaneously hypertensive rats (SHRs). ANG II increased COX-2 and pre-pro-ET-1 levels more in cultured vascular smooth muscle cells from hypertensive rats compared with normotensive rats. The ETA receptor antagonist BQ-123 reduced ANG II-induced COX-2 expression in SHR cells. ANG II also increased NOX-1 expression, NOX activity, and superoxide production in SHR cells; the selective NOX-1 inhibitor ML-171 and catalase reduced ANG II-induced COX-2 and ET-1 transcription. ANG II also increased c-Jun transcription and phospho-JNK1/2, phospho-c-Jun, and p65 NF-κB subunit nuclear protein expression. SP-600125 and lactacystin, JNK and NF-κB inhibitors, respectively, reduced ANG II-induced ET-1, COX-2, and NOX-1 levels and NOX activity. Pioglitazone reduced the effects of ANG II on NOX activity, NOX-1, pre-pro-ET-1, COX-2, and c-Jun mRNA levels, JNK activation, and nuclear phospho-c-Jun and p65 expression. In conclusion, ROS production and ET-1 are involved in ANG II-induced COX-2 expression in SHRs, explaining the greater COX-2 expression observed in this strain. Furthermore, pioglitazone inhibits ANG II-induced COX-2 expression likely by interfering with NF-κB and activator protein-1 proinflammatory pathways and downregulating ROS production and ET-1 transcription, thus contributing to the anti-inflammatory properties of glitazones.

  2. Heterogeneous gene expression changes in colorectal cancer cells share the WNT pathway in response to growth suppression by APHS-mediated COX-2 inhibition

    PubMed Central

    Humar, Bostjan; McNoe, Les; Dunbier, Anita; Heathcott, Rosemary; Braithwaite, Antony W; Reeve, Anthony E

    2008-01-01

    Cyclooxygenase-2 (COX-2), the prostaglandin (PG)-synthesizing enzyme overexpressed in colorectal cancer (CRC), has pleiotropic, cancer-promoting effects. COX-2 inhibitors (CIBs) interfere with many cancer-associated processes and show promising antineoplastic activity, however, a common mechanism of CIB action has not yet been established. We therefore investigated by microarray the global response towards the CIB APHS at a dose significantly inhibiting the growth of three COX-2-positive CRC but not of two COX-2-negative cell lines. None of the genes significantly (p = 0.005) affected by APHS were common to all three cell lines and 83% of the altered pathways were cell line-specific. Quantitative polymerase chain reaction (QPCR) on selected pathways confirmed cell line-specific expression alterations induced by APHS. A low stringency data analysis approach using BRB array tools coupled with QPCR, however, identified small expression changes shared by all COX-2-positive cell lines in genes related to the WNT pathway, the key driver of colonic carcinogenesis. Our data indicates a substantial cell line-specificity of APHS-induced expression alterations in CRC cells and helps to explain the divergent effects reported for CIBs. Further, the shared inhibition of the WNT pathway by APHS suggests one potential common mechanism behind the antineoplastic effects of COX-2 inhibition. PMID:19707365

  3. COX-2 and PPAR-γ confer cannabidiol-induced apoptosis of human lung cancer cells.

    PubMed

    Ramer, Robert; Heinemann, Katharina; Merkord, Jutta; Rohde, Helga; Salamon, Achim; Linnebacher, Michael; Hinz, Burkhard

    2013-01-01

    The antitumorigenic mechanism of cannabidiol is still controversial. This study investigates the role of COX-2 and PPAR-γ in cannabidiol's proapoptotic and tumor-regressive action. In lung cancer cell lines (A549, H460) and primary cells from a patient with lung cancer, cannabidiol elicited decreased viability associated with apoptosis. Apoptotic cell death by cannabidiol was suppressed by NS-398 (COX-2 inhibitor), GW9662 (PPAR-γ antagonist), and siRNA targeting COX-2 and PPAR-γ. Cannabidiol-induced apoptosis was paralleled by upregulation of COX-2 and PPAR-γ mRNA and protein expression with a maximum induction of COX-2 mRNA after 8 hours and continuous increases of PPAR-γ mRNA when compared with vehicle. In response to cannabidiol, tumor cell lines exhibited increased levels of COX-2-dependent prostaglandins (PG) among which PGD(2) and 15-deoxy-Δ(12,14)-PGJ(2) (15d-PGJ(2)) caused a translocation of PPAR-γ to the nucleus and induced a PPAR-γ-dependent apoptotic cell death. Moreover, in A549-xenografted nude mice, cannabidiol caused upregulation of COX-2 and PPAR-γ in tumor tissue and tumor regression that was reversible by GW9662. Together, our data show a novel proapoptotic mechanism of cannabidiol involving initial upregulation of COX-2 and PPAR-γ and a subsequent nuclear translocation of PPAR-γ by COX-2-dependent PGs.

  4. Comparative Proteomic Study of Fatty Acid-treated Myoblasts Reveals Role of Cox-2 in Palmitate-induced Insulin Resistance.

    PubMed

    Chen, Xiulan; Xu, Shimeng; Wei, Shasha; Deng, Yaqin; Li, Yiran; Yang, Fuquan; Liu, Pingsheng

    2016-02-22

    Accumulated studies demonstrate that saturated fatty acids (FAs) such as palmitic acid (PA) inhibit insulin signaling in skeletal muscle cells and monounsaturated fatty acids such as oleic acid (OA) reverse the effect of PA on insulin signaling. The detailed molecular mechanism of these opposite effects remains elusive. Here we provide a comparative proteomic study of skeletal myoblast cell line C2C12 that were untreated or treated with PA, and PA plus OA. A total of 3437 proteins were quantified using SILAC in this study and 29 proteins fall into the pattern that OA reverses PA effect. Expression of some these proteins were verified using qRT-PCR and Western blot. The most significant change was cyclooxygenase-2 (Cox-2). In addition to whole cell comparative proteomic study, we also compared lipid droplet (LD)-associated proteins and identified that Cox-2 was one of three major altered proteins under the FA treatment. This finding was then confirmed using immunofluorescence. Finally, Cox-2 selective inhibitor, celecoxib protected cells from PA-reduced insulin signaling Akt phosphorylation. Together, these results not only provide a dataset of protein expression change in FA treatment but also suggest that Cox-2 and lipid droplets (LDs) are potential players in PA- and OA-mediated cellular processes.

  5. Immunohistochemical detection of COX-2 in feline and canine actinic keratoses and cutaneous squamous cell carcinoma.

    PubMed

    Bardagí, M; Fondevila, D; Ferrer, L

    2012-01-01

    Cyclooxygenase-2 (COX-2) overexpression and its causal role in epidermal carcinogenesis have been demonstrated in human actinic keratoses (AK) and cutaneous squamous cell carcinoma (SCC). The aim of this study was to determine immunohistochemically the level of expression of COX-2 in feline and canine AK (n=18), SCC (n=36) and inflammatory dermatoses (n=24). COX-2 immunoreactivity was detected in all feline and canine SCC. In all specimens, labelled basal and suprabasal neoplastic keratinocytes were localized within and below areas of superficial erosion or ulceration and only scattered deeper tumour cells were positively labelled. In most cases, positive immunoreactivity of keratinocytes was associated with the presence of granulocytes. COX-2 expression was detected in 3/9 canine and 4/9 feline cases of AK and in only one case was associated with inflammation. Inflammatory dermatoses were characterized by positively labelled epidermal and follicular basal and suprabasal keratinocytes that were always associated with granulocyte exocytosis. These results indicate that further study of the effect of using COX-2 inhibitors in the management and prevention of feline and canine cutaneous SCC is warranted. The association between inflammatory cells and COX-2 expressing epidermal cells opens a new line of research regarding the role of COX-2 in SCC oncogenesis. Moreover, further studies should investigate the role of COX-2 in the pathogenesis and management of AK in animals.

  6. Cyclooxygenase (COX)-1 and COX-2 both play an important role in the protection of the duodenal mucosa in cats.

    PubMed

    Satoh, Hiroshi; Amagase, Kikuko; Ebara, Satomi; Akiba, Yasutada; Takeuchi, Koji

    2013-01-01

    Although nonsteroidal anti-inflammatory drugs often cause ulcers in the duodenum in humans, the role of cyclooxygenase (COX) isoforms in the pathogenesis of duodenal ulcers has not been fully elucidated. We examined in cats the 1) ulcerogenic effects of selective COX-1 (SC-560, ketorolac) and COX-2 (celecoxib, meloxicam) inhibitors on the gastrointestinal mucosa, 2) effect of feeding and cimetidine on the expression of COX isoforms and prostaglandin E(2) (PGE(2)) level in the duodenum, and 3) localization of COX isoforms in the duodenum. COX inhibitors were administered after the morning meal in cats once daily for 3 days. Gastrointestinal lesions were examined on day 4. Localization and expression of COX isoforms (by immunohistochemistry, Western blot) and PGE(2) level (by enzyme immunoassay) were examined. Results were as follows. First, selective COX-1 or COX-2 inhibitors alone produced marked ulcers in the duodenum but did not cause obvious lesions in the small intestine. Coadministration of SC-560 and celecoxib produced marked lesions in the small intestine. Second, feeding increased both the expression of COX isoforms and PGE(2) level in the duodenum, and the effects were markedly inhibited by pretreatment with cimetidine. Third, COX-1 was localized in goblet and Brunner's gland cells, Meissner's and Auerbach's plexus, smooth muscle cells, and arterioles; and COX-2 was observed in capillaries, venules, and basal granulated cells. The expression of COX isoforms in the duodenum is up-regulated by feeding, and inhibition of either COX-1 or COX-2 causes ulcers in the duodenum, suggesting that both isoforms play an important role in the protection of the duodenal mucosa.

  7. Assessment of the relative contribution of COX-1 and COX-2 isoforms to ischemia-induced oxidative damage and neurodegeneration following transient global cerebral ischemia.

    PubMed

    Candelario-Jalil, Eduardo; González-Falcón, Armando; García-Cabrera, Michel; Alvarez, Dalia; Al-Dalain, Said; Martínez, Gregorio; León, Olga Sonia; Springer, Joe E

    2003-08-01

    We investigated the relative contribution of COX-1 and/or COX-2 to oxidative damage, prostaglandin E2 (PGE2) production and hippocampal CA1 neuronal loss in a model of 5 min transient global cerebral ischemia in gerbils. Our results revealed a biphasic and significant increase in PGE2 levels after 2 and 24-48 h of reperfusion. The late increase in PGE2 levels (24 h) was more potently reduced by the highly selective COX-2 inhibitor rofecoxib (20 mg/kg) relative to the COX-1 inhibitor valeryl salicylate (20 mg/kg). The delayed rise in COX catalytic activity preceded the onset of histopathological changes in the CA1 subfield of the hippocampus. Post-ischemia treatment with rofecoxib (starting 6 h after restoration of blood flow) significantly reduced measures of oxidative damage (glutathione depletion and lipid peroxidation) seen at 48 h after the initial ischemic episode, indicating that the late increase in COX-2 activity is involved in the delayed occurrence of oxidative damage in the hippocampus after global ischemia. Interestingly, either selective inhibition of COX-2 with rofecoxib or inhibition of COX-1 with valeryl salicylate significantly increased the number of healthy neurons in the hippocampal CA1 sector even when the treatment began 6 h after ischemia. These results provide the first evidence that both COX isoforms are involved in the progression of neuronal damage following global cerebral ischemia, and have important implications for the potential therapeutic use of COX inhibitors in cerebral ischemia.

  8. Selective Inhibitors of Protein Methyltransferases

    PubMed Central

    2015-01-01

    Mounting evidence suggests that protein methyltransferases (PMTs), which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and human diseases. In particular, PMTs have been recognized as major players in regulating gene expression and chromatin state. PMTs are divided into two categories: protein lysine methyltransferases (PKMTs) and protein arginine methyltransferases (PRMTs). There has been a steadily growing interest in these enzymes as potential therapeutic targets and therefore discovery of PMT inhibitors has also been pursued increasingly over the past decade. Here, we present a perspective on selective, small-molecule inhibitors of PMTs with an emphasis on their discovery, characterization, and applicability as chemical tools for deciphering the target PMTs’ physiological functions and involvement in human diseases. We highlight the current state of PMT inhibitors and discuss future directions and opportunities for PMT inhibitor discovery. PMID:25406853

  9. Radiation-induced non-targeted response in vivo: role of the TGFβ-TGFBR1-COX-2 signalling pathway

    PubMed Central

    Chai, Y; Lam, R K K; Calaf, G M; Zhou, H; Amundson, S; Hei, T K

    2013-01-01

    Background: Previous studies from our group and others have shown that cyclooxygenase-2 (COX-2) has an essential role in radiation-induced non-targeted responses and genomic instability in vivo. However, the signalling pathways involved in such effects remain unclear. Methods: A 1 cm2 area (1 cm × 1 cm) in the lower abdominal region of gpt delta transgenic mice was irradiated with 5 Gy of 300 keV X-rays. Nimesulide, a selective COX-2 inhibitor, was given to mice for five consecutive days before irradiation. Changes in transforming growth factor-beta (TGF-β) and TGF-β receptor type-1 (TGFBR1) mediated signalling pathways, in the out of radiation field lung and liver tissues were examined. Results: While the plasma level of cytokines remained unchanged, the expression of TGF-β and its receptors was elevated in non-targeted lung tissues after partial body irradiation. In contrast to the predominant expression of TGF-β in stromal and alveolar cells, but not in bronchial epithelial cells, TGF-β receptors, especially TGFBR1 were significantly elevated in non-targeted bronchial epithelial cells, which is consistent with the induction of COX-2. The different expression levels of TGFBR1 between liver and lung resulted in a tissue specific induction of COX-2 in these two non-targeted tissues. Multiple TGF-β induced signalling pathways were activated in the non-targeted lung tissues. Conclusion: The TGFβ-TGFBR1-COX-2 Signalling Pathway has a critical role in radiation-induced non-targeted response in vivo. PMID:23412109

  10. COX-2 verexpression in pretreatment biopsies predicts response of rectal cancers to neoadjuvant radiochemotherapy

    SciTech Connect

    Smith, Fraser M.; Reynolds, John V. . E-mail: reynoldsjv@stjames.ie; Kay, Elaine W.; Crotty, Paul; Murphy, James O.; Hollywood, Donal; Gaffney, Eoin F.; Stephens, Richard B.; Kennedy, M. John

    2006-02-01

    Purpose: To determine the utility of COX-2 expression as a response predictor for patients with rectal cancer who are undergoing neoadjuvant radiochemotherapy (RCT). Methods and Materials: Pretreatment biopsies (PTB) from 49 patients who underwent RCT were included. COX-2 and proliferation in PTB were assessed by immunohistochemistry (IHC) and apoptosis was detected by TUNEL stain. Response to treatment was assessed by a 5-point tumor-regression grade (TRG) based on the ratio of residual tumor to fibrosis. Results: Good response (TRG 1 + 2), moderate response (TRG 3), and poor response (TRG 4 + 5) were seen in 21 patients (42%), 11 patients (22%), and 17 patients (34%), respectively. Patients with COX-2 overexpression in PTB were more likely to demonstrate moderate or poor response (TRG 3 + 4) to treatment than were those with normal COX-2 expression (p = 0.026, chi-square test). Similarly, poor response was more likely if patients had low levels of spontaneous apoptosis in PTBs (p = 0.0007, chi-square test). Conclusions: COX-2 overexpression and reduced apoptosis in PTB can predict poor response of rectal cancer to RCT. As COX-2 inhibitors are commercially available, their administration to patients who overexpress COX-2 warrants assessment in clinical trials in an attempt to increase overall response rates.

  11. Demethoxycurcumin Preserves Renovascular Function by Downregulating COX-2 Expression in Hypertension

    PubMed Central

    2016-01-01

    Hypertension-associated endothelial dysfunction is largely due to the exaggerated vasoconstrictor generation by cyclooxygenase-2 (COX-2). COX-2 is induced under inflammatory condition. Demethoxycurcumin (DMC) is a major component of Curcuma longa L, which possesses anti-inflammatory action. This study aimed to examine whether DMC protects endothelial function in hypertension by modulating COX-2. Changes in isometric tension showed that in vivo and ex vivo treatment with DMC rescued the attenuated endothelium-dependent relaxations (EDRs) and elevated endothelium-dependent contractions (EDCs) in the renal arteries of SHR, which were also corrected by acute usage of the COX-2 inhibitor celecoxib. The restoration of renovascular activity by DMC was accompanied by the normalization of COX-2 expression. The enhanced COX-2 expression observed in the renal arteries of hypertensive patients was suppressed by incubation of excised arteries with DMC for 12 hrs. In the renal arteries of Wistar-Kyoto rats (WKY), DMC prevented the endothelial dysfunction caused by angiotensin II. The reduction in the generation of nitric oxide (NO) and expression of eNOS phosphorylation (Ser1177) in human umbilical vein endothelial cells caused by angiotensin II (Ang II) were restored by DMC or celecoxib. Our findings suggest that DMC may decrease COX-2 expression and improve endothelial function in hypertension. PMID:28105253

  12. Molecular Dynamics Simulations of Arachidonic Acid-Derived Pentadienyl Radical Intermediate Complexes with COX-1 and COX-2

    PubMed Central

    Furse, Kristina E.; Pratt, Derek A.; Schneider, Claus; Brash, Alan R.; Porter, Ned A.; Lybrand, Terry P.

    2008-01-01

    The two cyclooxygenase enzymes, COX-1 and COX-2, are responsible for the committed step in prostaglandin biosynthesis, and are the targets of the non-steroidal anti-inflammatory drugs aspirin, ibuprofen and the COX-2 selective inhibitors, Celebrex™, Vioxx™ and Bextra™. The enzymes are remarkable in that they catalyze two dioxygenations and two cyclizations of the native substrate, arachidonic acid, with near absolute regio- and stereoselectivity. Several theories have been advanced to explain the nature of enzymatic control over this series of reactions, including suggestions of steric shielding and oxygen channeling. As proposed here, selective radical trapping and spin localization in the substrate-derived pentadienyl radical intermediate can also be envisioned. Herein we describe the results of explicit, 10 ns molecular dynamics simulations of both COX-1 and COX-2 with the substrate-derived pentadienyl radical intermediate bound in the active site. The enzymes’ influence on the conformation of the pentadienyl radical was investigated, along with the accessible space above and below the radical plane, and the width of several channels to the active site that could function as access routes for molecular oxygen. Additional simulations demonstrated the extent of molecular oxygen mobility within the active site. The results suggest that spin localization is unlikely to play a role in enzymatic control of this reaction. Instead, a combination of oxygen channeling, steric shielding and selective radical trapping appears to be responsible. This work adds a dynamic perspective to the strong foundation of static structural data available for these enzymes. PMID:16519515

  13. Celecoxib Induced Tumor Cell Radiosensitization by Inhibiting Radiation Induced Nuclear EGFR Transport and DNA-Repair: A COX-2 Independent Mechanism

    SciTech Connect

    Dittmann, Klaus H. Mayer, Claus; Ohneseit, Petra A.; Raju, Uma; Andratschke, Nickolaus H.; Milas, Luka; Rodemann, H. Peter

    2008-01-01

    Purpose: The purpose of the study was to elucidate the molecular mechanisms mediating radiosensitization of human tumor cells by the selective cyclooxygenase (COX)-2 inhibitor celecoxib. Methods and Materials: Experiments were performed using bronchial carcinoma cells A549, transformed fibroblasts HH4dd, the FaDu head-and-neck tumor cells, the colon carcinoma cells HCT116, and normal fibroblasts HSF7. Effects of celecoxib treatment were assessed by clonogenic cell survival, Western analysis, and quantification of residual DNA damage by {gamma}H{sub 2}AX foci assay. Results: Celecoxib treatment resulted in a pronounced radiosensitization of A549, HCT116, and HSF7 cells, whereas FaDu and HH4dd cells were not radiosensitized. The observed radiosensitization could neither be correlated with basal COX-2 expression pattern nor with basal production of prostaglandin E2, but was depended on the ability of celecoxib to inhibit basal and radiation-induced nuclear transport of epidermal growth factor receptor (EGFR). The nuclear EGFR transport was strongly inhibited in A549-, HSF7-, and COX-2-deficient HCT116 cells, which were radiosensitized, but not in FaDu and HH4dd cells, which resisted celecoxib-induced radiosensitization. Celecoxib inhibited radiation-induced DNA-PK activation in A549, HSF7, and HCT116 cells, but not in FaDu and HH4dd cells. Consequentially, celecoxib increased residual {gamma}H2AX foci after irradiation, demonstrating that inhibition of DNA repair has occurred in responsive A549, HCT116, and HSF7 cells only. Conclusions: Celecoxib enhanced radiosensitivity by inhibition of EGFR-mediated mechanisms of radioresistance, a signaling that was independent of COX-2 activity. This novel observation may have therapeutic implications such that COX-2 inhibitors may improve therapeutic efficacy of radiation even in patients whose tumor radioresistance is not dependent on COX-2.

  14. Staurosporine synergistically potentiates the deoxycholate-mediated induction of COX-2 expression.

    PubMed

    Saeki, Tohru; Inui, Haruka; Fujioka, Saya; Fukuda, Suguru; Nomura, Ayumi; Nakamura, Yasushi; Park, Eun Young; Sato, Kenji; Kanamoto, Ryuhei

    2014-08-01

    Colorectal cancer is a major cause of cancer-related death in western countries, and thus there is an urgent need to elucidate the mechanism of colorectal tumorigenesis. A diet that is rich in fat increases the risk of colorectal tumorigenesis. Bile acids, which are secreted in response to the ingestion of fat, have been shown to increase the risk of colorectal tumors. The expression of cyclooxygenase (COX)-2, an inducible isozyme of cyclooxygenase, is induced by bile acids and correlates with the incidence and progression of cancers. In this study, we investigated the signal transduction pathways involved in the bile-acid-mediated induction of COX-2 expression. We found that staurosporine (sts), a potent protein kinase C (PKC) inhibitor, synergistically potentiated the deoxycholate-mediated induction of COX-2 expression. Sts did not increase the stabilization of COX-2 mRNA. The sts- and deoxycholate-mediated synergistic induction of COX-2 expression was suppressed by a membrane-permeable Ca(2+) chelator, a phosphoinositide 3-kinase inhibitor, a nuclear factor-κB pathway inhibitor, and inhibitors of canonical and stress-inducible mitogen-activated protein kinase pathways. Inhibition was also observed using PKC inhibitors, suggesting the involvement of certain PKC isozymes (η, θ, ι, ζ, or μ). Our results indicate that sts exerts its potentiating effects via the phosphorylation of p38. However, the effects of anisomycin did not mimic those of sts, indicating that although p38 activation is required, it does not enhance deoxycholate-induced COX-2 expression. We conclude that staurosporine synergistically enhances deoxycholate-induced COX-2 expression in RCM-1 colon cancer cells.

  15. Minimizing the cancer-promotional activity of cox-2 as a central strategy in cancer prevention.

    PubMed

    McCarty, Mark F

    2012-01-01

    A recent meta-analysis examining long-term mortality in subjects who participated in controlled studies evaluating the impact of daily aspirin on vascular risk, has concluded that aspirin confers substantial protection from cancer mortality. Remarkably, low-dose aspirin was as effective as higher-dose regimens; hence this protection may be achievable with minimal risk. There is reason to believe that this protection stems primarily from inhibition of cox-2 in pre-neoplastic lesions. Since safe aspirin regimens can only achieve a partial and transitory inhibition of cox-2, it may be feasible to complement the cancer-protective benefit of aspirin with other measures which decrease cox-2 expression or which limit the bioactivity of cox-2-derived PGE2. Oxidative stress boosts cox-2 expression by up-regulating activation of NF-kappaB and MAP kinases; NADPH oxidase activation may thus promote carcinogenesis by increasing cox-2 expression while also amplifying oxidant-mediated mutagenesis. A prospective cohort study has observed that relatively elevated serum bilirubin levels are associated with a marked reduction in subsequent cancer mortality; this may reflect bilirubin's physiological role as a potent inhibitor of NADPH oxidase. It may be feasible to mimic this protective effect by supplementing with spirulina, a rich source of a phycobilin which shares bilirubin's ability to inhibit NADPH oxidase. Ancillary antioxidant measures - phase 2 inducing phytochemicals, melatonin, N-acetylcysteine, and astaxanthin - may also aid cox-2 down-regulation. The cancer protection often associated with high-normal vitamin D status may be attributable, in part, to the ability of the activated vitamin D receptor to decrease cox-2 expression while promoting PGE2 catabolism and suppressing the expression of PGE2 receptors. Diets with a relatively low ratio of omega-6 to long-chain omega-3 fats may achieve cancer protection by antagonizing the production and bioactivity of PGE2. Growth

  16. Cox-2 Inhibition Protects against Hypoxia/Reoxygenation-Induced Cardiomyocyte Apoptosis via Akt-Dependent Enhancement of iNOS Expression

    PubMed Central

    Cai, Yin; Tang, Eva Hoi Ching; Yan, Dan; Kosuru, Ramoji

    2016-01-01

    The present study explored the potential causal link between ischemia-driven cyclooxygenase-2 (COX-2) expression and enhanced apoptosis during myocardial ischemia/reperfusion (I/R) by using H9C2 cardiomyocytes and primary rat cardiomyocytes subjected to hypoxia/reoxygenation (H/R). The results showed that H/R resulted in higher COX-2 expression than that of controls, which was prevented by pretreatment with Helenalin (NFκB specific inhibitor). Furthermore, pretreatment with NS398 (COX-2 specific inhibitor) significantly attenuated H/R-induced cell injury [lower lactate dehydrogenase (LDH) leakage and enhanced cell viability] and apoptosis (higher Bcl2 expression and lower level of cleaved caspases-3 and TUNEL-positive cells) in cardiomyocytes. The amelioration of posthypoxic apoptotic cell death was paralleled by significant attenuation of H/R-induced increases in proinflammatory cytokines [interleukin 6 (IL6) and tumor necrosis factor (TNFα)] and reactive oxygen species (ROS) production and by higher protein expression of phosphorylated Akt and inducible nitric oxide synthase (iNOS) and enhanced nitric oxide production. Moreover, the application of LY294002 (Akt-specific inhibitor) or 1400W (iNOS-selective inhibitor) cancelled the cellular protective effects of NS398. Findings from the current study suggest that activation of NFκB during cardiomyocyte H/R induces the expression of COX-2 and that higher COX-2 expression during H/R exacerbates cardiomyocyte H/R injury via mechanisms that involve cross talks among inflammation, ROS, and Akt/iNOS/NO signaling. PMID:27795807

  17. UVB Radiation-Induced β-catenin Signaling is Enhanced by COX-2 Expression in Keratinocytes

    PubMed Central

    Smith, Kimberly A.; Tong, Xin; Abu-Yousif, Adnan O.; Mikulec, Carol C.; Gottardi, Cara J.; Fischer, Susan M.; Pelling, Jill C.

    2014-01-01

    UVB radiation is the major carcinogen responsible for skin carcinogenesis, thus elucidation of the molecular pathways altered in skin in response to UVB would reveal novel targets for therapeutic intervention. It is well established that UVB leads to upregulation of cyclooxygenase 2 (COX-2) in the skin which contributes to skin carcinogenesis. Overexpression of COX-2 has been shown to promote colon cancer cell growth through β-catenin signaling, however, little is known about the connection between UVB, COX-2 and β-catenin in the skin. In the present study, we have identified a novel pathway in which UVB induces β-catenin signaling in keratinocytes, which is modulated by COX-2 expression. Exposure of the mouse 308 keratinocyte cell line (308 cells) and primary normal human epidermal keratinocytes (NHEKs) to UVB resulted in increased protein levels of both N-terminally unphosphorylated and total β-catenin. In addition, we found that UVB enhanced β-catenin-dependent TOPflash reporter activity and expression of a downstream β-catenin target gene. We demonstrated that UVB-induced β-catenin signaling is modulated by COX-2, as treatment of keratinocytes with the specific COX-2 inhibitor NS398 blocked UVB induction of β-catenin. Additionally, β-catenin target gene expression was reduced in UVB-treated COX-2 knockout (KO) MEFs compared to wild-type (WT) MEFs. Furthermore, epidermis from UVB-exposed SKH-1 mice exhibited increased N-terminally unphosphorylated and total β-catenin protein levels and increased staining for total β-catenin, and both responses were reduced in COX-2 heterozygous mice. Taken together, these results suggest a novel pathway in which UVB induces β-catenin signaling in keratinocytes which is enhanced by COX-2 expression. PMID:21853475

  18. A pharmacokinetic/pharmacodynamic approach vs. a dose titration for the determination of a dosage regimen: the case of nimesulide, a Cox-2 selective nonsteroidal anti-inflammatory drug in the dog.

    PubMed

    Toutain, P L; Cester, C C; Haak, T; Laroute, V

    2001-02-01

    The present experiment was designed to determine a dosage regimen (dose, interval of administration) in the dog for nimesulide, a nonsteroidal anti-inflammatory drug with in vitro selectivity for the inhibition of cyclo-oxygenase 2 (Cox-2), using a pharmacokinetic/pharmacodynamic (PK/PD) approach. The PK/PD results were compared with those obtained using a classical dose titration study. In the PK/PD experiment, 11 dogs were subjected to Freund's adjuvant arthritis characterized by permanent hyperthermia. Nimesulide (5 mg/kg, oral route) was tested during the secondary phase of the inflammatory response. In the dose titration study, nimesulide (0, 3, 6 and 9 mg/kg, oral route) was tested in eight other dogs using a reversible urate crystal arthritis in a 4-period crossover design. Different PD endpoints (including lameness assessed by force plate and hyperthermia) were regularly measured during the PK/PD experiment, and plasma samples were obtained to determine the plasma nimesulide concentration. The data were modeled using an indirect effect model. The IC50 of nimesulide for lameness was 6.26 +/- 3.01 microg/mL, which was significantly higher than the EC50 value obtained for antipyretic effect (2.72 +/- 1.29 microg/mL). The ED50 estimated from the classical dose titration study were 1.34 mg/kg (lameness) and 3.0 mg/kg (skin temperature). The PK/PD parameters were used to simulate different dosage regimens (dose, interval of administration). The antipyretic and anti-inflammatory effects were calculated from the model for the recommended dosage regimen (5 mg/kg/24 h). It was apparent from this approach, that this dosage regimen enabled 76% of the theoretical maximal drug efficacy to be obtained for pyresis and 43% for lameness. It was concluded from the comparison of in vivo and in vitro IC50, that nimesulide is a potent NSAID for which some Cox-1 inhibition is required to obtain clinically relevant efficacy.

  19. COX-2 Induces Breast Cancer Stem Cells via EP4/PI3K/AKT/NOTCH/WNT Axis.

    PubMed

    Majumder, Mousumi; Xin, Xiping; Liu, Ling; Tutunea-Fatan, Elena; Rodriguez-Torres, Mauricio; Vincent, Krista; Postovit, Lynne-Marie; Hess, David; Lala, Peeyush K

    2016-09-01

    Cancer stem-like cells (SLC) resist conventional therapies, necessitating searches for SLC-specific targets. We established that cyclo-oxygenase(COX)-2 expression promotes human breast cancer progression by activation of the prostaglandin(PG)E-2 receptor EP4. Present study revealed that COX-2 induces SLCs by EP4-mediated NOTCH/WNT signaling. Ectopic COX-2 over-expression in MCF-7 and SKBR-3 cell lines resulted in: increased migration/invasion/proliferation, epithelial-mesenchymal transition (EMT), elevated SLCs (spheroid formation), increased ALDH activity and colocalization of COX-2 and SLC markers (ALDH1A, CD44, β-Catenin, NANOG, OCT3/4, SOX-2) in spheroids. These changes were reversed with COX-2-inhibitor or EP4-antagonist (EP4A), indicating dependence on COX-2/EP4 activities. COX-2 over-expression or EP4-agonist treatments of COX-2-low cells caused up-regulation of NOTCH/WNT genes, blocked with PI3K/AKT inhibitors. NOTCH/WNT inhibitors also blocked COX-2/EP4 induced SLC induction. Microarray analysis showed up-regulation of numerous SLC-regulatory and EMT-associated genes. MCF-7-COX-2 cells showed increased mammary tumorigenicity and spontaneous multiorgan metastases in NOD/SCID/IL-2Rγ-null mice for successive generations with limiting cell inocula. These tumors showed up-regulation of VEGF-A/C/D, Vimentin and phospho-AKT, down-regulation of E-Cadherin and enrichment of SLC marker positive and spheroid forming cells. MCF-7-COX-2 cells also showed increased lung colonization in NOD/SCID/GUSB-null mice, an effect reversed with EP4-knockdown or EP4A treatment of the MCF-7-COX-2 cells. COX-2/EP4/ALDH1A mRNA expression in human breast cancer tissues were highly correlated with one other, more marked in progressive stage of disease. In situ immunostaining of human breast tumor tissues revealed co-localization of SLC markers with COX-2, supporting COX-2 inducing SLCs. High COX-2/EP4 mRNA expression was linked with reduced survival. Thus, EP4 represents a novel SLC

  20. Opioid-sparing effect of selective cyclooxygenase-2 inhibitors on surgical outcomes after open colorectal surgery within an enhanced recovery after surgery protocol

    PubMed Central

    Lohsiriwat, Varut

    2016-01-01

    AIM: To evaluate the opioid-sparing effect of selective cyclooxygenase-2 (COX-2) inhibitors on short-term surgical outcomes after open colorectal surgery. METHODS: Patients undergoing open colorectal resection within an enhanced recovery after surgery protocol from 2011 to 2015 were reviewed. Patients with combined general anesthesia and epidural anesthesia, and those with acute colonic obstruction or perforation were excluded. Patients receiving selective COX-2 inhibitor were compared with well-matched individuals without such a drug. Outcome measures included numeric pain score and morphine milligram equivalent (MME) consumption on postoperative day (POD) 1-3, gastrointestinal recovery (time to tolerate solid diet and time to defecate), complications and length of postoperative stay. RESULTS: There were 75 patients in each group. Pain score on POD 1-3 was not significantly different between two groups. However, MME consumption and MME consumption per kilogram body weight on POD 1-3 was significantly less in patients receiving a selective COX-2 inhibitor (P < 0.001). Median MME consumption per kilogram body weight on POD 1-3 was 0.09, 0.06 and nil, respectively in patients receiving a selective COX-2 inhibitor and 0.22, 0.25 and 0.07, respectively in the comparative group (P < 0.001), representing at least 59% opioid reduction. Patients prescribing a selective COX-2 inhibitor had a shorter median time to resumption of solid diet [1 (IQR 1-2) d vs 2 (IQR 2-3) d; P < 0.001] and time to first defecation [2 (IQR 2-3) d vs 3 (IQR 3-4) d; P < 0.001]. There was no significant difference in overall postoperative complications between two groups. However, median postoperative stay was significantly 1-d shorter in patients prescribing a selective COX-2 inhibitor [4 (IQR 3-5) d vs 5 (IQR 4-6) d; P < 0.001]. CONCLUSION: Perioperative administration of oral selective COX-2 inhibitors significantly decreased intravenous opioid consumption, shortened time to gastrointestinal

  1. Interaction of apoptotic cells with macrophages upregulates COX-2/PGE2 and HGF expression via a positive feedback loop.

    PubMed

    Byun, Ji Yeon; Youn, Young-So; Lee, Ye-Ji; Choi, Youn-Hee; Woo, So-Yeon; Kang, Jihee Lee

    2014-01-01

    Recognition of apoptotic cells by macrophages is crucial for resolution of inflammation, immune tolerance, and tissue repair. Cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and hepatocyte growth factor (HGF) play important roles in the tissue repair process. We investigated the characteristics of macrophage COX-2 and PGE2 expression mediated by apoptotic cells and then determined how macrophages exposed to apoptotic cells in vitro and in vivo orchestrate the interaction between COX-2/PGE2 and HGF signaling pathways. Exposure of RAW 264.7 cells and primary peritoneal macrophages to apoptotic cells resulted in induction of COX-2 and PGE2. The COX-2 inhibitor NS-398 suppressed apoptotic cell-induced PGE2 production. Both NS-398 and COX-2-siRNA, as well as the PGE2 receptor EP2 antagonist, blocked HGF expression in response to apoptotic cells. In addition, the HGF receptor antagonist suppressed increases in COX-2 and PGE2 induction. The in vivo relevance of the interaction between the COX-2/PGE2 and HGF pathways through a positive feedback loop was shown in cultured alveolar macrophages following in vivo exposure of bleomycin-stimulated lungs to apoptotic cells. Our results demonstrate that upregulation of the COX-2/PGE2 and HGF in macrophages following exposure to apoptotic cells represents a mechanism for mediating the anti-inflammatory and antifibrotic consequences of apoptotic cell recognition.

  2. Inhibition of COX-2/PGE2 cascade ameliorates cisplatin-induced mesangial cell apoptosis

    PubMed Central

    Yu, Xiaowen; Yang, Yunwen; Yuan, Hui; Wu, Meng; Li, Shuzhen; Gong, Wei; Yu, Jing; Xia, Weiwei; Zhang, Yue; Ding, Guixia; Huang, Songming; Jia, Zhanjun; Zhang, Aihua

    2017-01-01

    Cisplatin is one of the most potent cytotoxic drug for the treatment of many types of cancer. However, the side effects on normal tissues, particularly on the kidney, greatly limited its use in clinic. Emerging evidence demonstrated that cisplatin could directly cause mesangial cell apoptosis, while the potential mechanism is still elusive. Here we examined the contribution of COX-2 in cisplatin-induced mesangial cell apoptosis. Firstly, we found cisplatin induced cell apoptosis in mesangial cells shown by increased number of apoptotic cells in parallel with the upregulation of Bax and the downregulation of Bcl-2. Interestingly, cisplatin-induced cell apoptosis was accompanied by an upregulation of COX-2 at both mRNA and protein levels in dose- and time-dependent manners. Importantly, inhibition of COX-2 via a specific COX-2 inhibitor celecoxib markedly blocked cisplatin-induced mesangial cell apoptosis as evidenced by the decreased number of apoptotic cells, blocked increments of cleaved caspase-3 and Bax, and reversed Bcl-2 downregulation. Meanwhile, cisplatin-induced PGE2 production was markedly blocked by the treatment of celecoxib. In conclusion, this study indicated that COX-2/PGE2 cascade activation mediated cisplatin-induced mesangial cell apoptosis. The findings not only offered new insights into the understanding of cisplatin nephrotoxicity but also provided the therapeutic potential by targeting COX-2/PGE2 cascade in treating cisplatin-induced kidney injury. PMID:28386348

  3. DPPC regulates COX-2 expression in monocytes via phosphorylation of CREB

    SciTech Connect

    Morris, R.H.K. Tonks, A.J.; Jones, K.P.; Ahluwalia, M.K.; Thomas, A.W.; Tonks, A.; Jackson, S.K.

    2008-05-23

    The major phospholipid in pulmonary surfactant dipalmitoyl phosphatidylcholine (DPPC) has been shown to modulate inflammatory responses. Using human monocytes, this study demonstrates that DPPC significantly increased PGE{sub 2} (P < 0.05) production by 2.5-fold when compared to untreated monocyte controls. Mechanistically, this effect was concomitant with an increase in COX-2 expression which was abrogated in the presence of a COX-2 inhibitor. The regulation of COX-2 expression was independent of NF-{kappa}B activity. Further, DPPC increased the phosphorylation of the cyclic AMP response element binding protein (CREB; an important nuclear transcription factor important in regulating COX-2 expression). In addition, we also show that changing the fatty acid groups of PC (e.g. using L-{alpha}-phosphatidylcholine {beta}-arachidonoyl-{gamma}-palmitoyl (PAPC)) has a profound effect on the regulation of COX-2 expression and CREB activation. This study provides new evidence for the anti-inflammatory activity of DPPC and that this activity is at least in part mediated via CREB activation of COX-2.

  4. Soman increases neuronal COX-2 levels: possible link between seizures and protracted neuronal damage.

    PubMed

    Angoa-Pérez, Mariana; Kreipke, Christian W; Thomas, David M; Van Shura, Kerry E; Lyman, Megan; McDonough, John H; Kuhn, Donald M

    2010-12-01

    Nerve agent-induced seizures cause neuronal damage in brain limbic and cortical circuits leading to persistent behavioral and cognitive deficits. Without aggressive anticholinergic and benzodiazepine therapy, seizures can be prolonged and neuronal damage progresses for extended periods of time. The objective of this study was to determine the effects of the nerve agent soman on expression of cyclooxygenase-2 (COX-2), the initial enzyme in the biosynthetic pathway of the proinflammatory prostaglandins and a factor that has been implicated in seizure initiation and propagation. Rats were exposed to a toxic dose of soman and scored behaviorally for seizure intensity. Expression of COX-2 was determined throughout brain from 4h to 7 days after exposure by immunohistochemistry and immunoblotting. Microglial activation and astrogliosis were assessed microscopically over the same time-course. Soman increased COX-2 expression in brain regions known to be damaged by nerve agents (e.g., hippocampus, amygdala, piriform cortex and thalamus). COX-2 expression was induced in neurons, and not in microglia or astrocytes, and remained elevated through 7 days. The magnitude of COX-2 induction was correlated with seizure intensity. COX-1 expression was not changed by soman. Increased expression of neuronal COX-2 by soman is a late-developing response relative to other signs of acute physiological distress caused by nerve agents. COX-2-mediated production of prostaglandins is a consequence of the seizure-induced neuronal damage, even after survival of the initial cholinergic crisis is assured. COX-2 inhibitors should be considered as adjunct therapy in nerve agent poisoning to minimize nerve agent-induced seizure activity.

  5. Soman Increases Neuronal COX-2 Levels: Possible Link between Seizures and Protracted Neuronal Damage

    PubMed Central

    Angoa-Pérez, Mariana; Kreipke, Christian W.; Thomas, David M.; Van Shura, Kerry E.; Lyman, Megan; McDonough, John H.; Kuhn, Donald M.

    2010-01-01

    Nerve agent-induced seizures cause neuronal damage in brain limbic and cortical circuits leading to persistent behavioral and cognitive deficits. Without aggressive anticholinergic and benzodiazepine therapy, seizures can be prolonged and neuronal damage progresses for extended periods of time. The objective of this study was to determine the effects of the nerve agent soman on expression of cyclooxygenase-2 (COX-2), the initial enzyme in the biosynthetic pathway of the proinflammatory prostaglandins and a factor that has been implicated in seizure initiation and propagation. Rats were exposed to a toxic dose of soman and scored behaviorally for seizure intensity. Expression of COX-2 was determined throughout brain from 4 hr to 7 days after exposure by immunohistochemistry and immunoblotting. Microglial activation and astrogliosis were assessed microscopically over the same time-course. Soman increased COX-2 expression in brain regions known to be damaged by nerve agents (e.g., hippocampus, amygdala, piriform cortex and thalamus). COX-2 expression was induced in neurons, and not in microglia or astrocytes, and remained elevated through 7 days. The magnitude of COX-2 induction was correlated with seizure intensity. COX-1 expression was not changed by soman. Increased expression of neuronal COX-2 by soman is a late-developing response relative to other signs of acute physiological distress caused by nerve agents. COX-2-mediated production of prostaglandins is a consequence of the seizure-induced neuronal damage, even after survival of the initial cholinergic crisis is assured. COX-2 inhibitors should be considered as adjunct therapy in nerve agent poisoning to minimize nerve agent-induced seizure activity. PMID:20600289

  6. PGE2 receptor EP2 mediates the antagonistic effect of COX-2 on TGF-beta signaling during mammary tumorigenesis.

    PubMed

    Tian, Maozhen; Schiemann, William P

    2010-04-01

    The molecular mechanisms that enable cyclooxygenase-2 (COX-2) and its mediator prostaglandin E2 (PGE2) to inhibit transforming growth factor-beta (TGF-beta) signaling during mammary tumorigenesis remain unknown. We show here that TGF-beta selectively stimulated the expression of the PGE2 receptor EP2, which increased normal and malignant mammary epithelial cell (MEC) invasion, anchorage-independent growth, and resistance to TGF-beta-induced cytostasis. Mechanistically, elevated EP2 expression in normal MECs inhibited the coupling of TGF-beta to Smad2/3 activation and plasminogen activator inhibitor-1 (PAI1) expression, while EP2 deficiency in these same MECs augmented Smad2/3 activation and PAI expression stimulated by TGF-beta. Along these lines, engineering malignant MECs to lack EP2 expression prevented their growth in soft agar, restored their cytostatic response to TGF-beta, decreased their invasiveness in response to TGF-beta, and potentiated their activation of Smad2/3 and expression of PAI stimulated by TGF-beta. More important, we show that COX-2 or EP2 deficiency both significantly decreased the growth, angiogenesis, and pulmonary metastasis of mammary tumors produced in mice. Collectively, this investigation establishes EP2 as a potent mediator of the anti-TGF-beta activities elicited by COX-2/PGE2 in normal and malignant MECs. Our findings also suggest that pharmacological targeting of EP2 receptors may provide new inroads to antagonize the oncogenic activities of TGF-beta during mammary tumorigenesis.-Tian, M., Schiemann, W. P. PGE2 receptor EP2 mediates the antagonistic effect of COX-2 on TGF-beta signaling during mammary tumorigenesis.

  7. PGE2 receptor EP2 mediates the antagonistic effect of COX-2 on TGF-β signaling during mammary tumorigenesis

    PubMed Central

    Tian, Maozhen; Schiemann, William P.

    2010-01-01

    The molecular mechanisms that enable cyclooxygenase-2 (COX-2) and its mediator prostaglandin E2 (PGE2) to inhibit transforming growth factor-β (TGF-β) signaling during mammary tumorigenesis remain unknown. We show here that TGF-β selectively stimulated the expression of the PGE2 receptor EP2, which increased normal and malignant mammary epithelial cell (MEC) invasion, anchorage-independent growth, and resistance to TGF-β-induced cytostasis. Mechanistically, elevated EP2 expression in normal MECs inhibited the coupling of TGF-β to Smad2/3 activation and plasminogen activator inhibitor-1 (PAI1) expression, while EP2 deficiency in these same MECs augmented Smad2/3 activation and PAI expression stimulated by TGF-β. Along these lines, engineering malignant MECs to lack EP2 expression prevented their growth in soft agar, restored their cytostatic response to TGF-β, decreased their invasiveness in response to TGF-β, and potentiated their activation of Smad2/3 and expression of PAI stimulated by TGF-β. More important, we show that COX-2 or EP2 deficiency both significantly decreased the growth, angiogenesis, and pulmonary metastasis of mammary tumors produced in mice. Collectively, this investigation establishes EP2 as a potent mediator of the anti-TGF-β activities elicited by COX-2/PGE2 in normal and malignant MECs. Our findings also suggest that pharmacological targeting of EP2 receptors may provide new inroads to antagonize the oncogenic activities of TGF-β during mammary tumorigenesis.—Tian, M., Schiemann, W. P. PGE2 receptor EP2 mediates the antagonistic effect of COX-2 on TGF-β signaling during mammary tumorigenesis. PMID:19897661

  8. Functional Polymorphisms in COX-2 Gene Are Correlated with the Risk of Oral Cancer

    PubMed Central

    Li, Dong; Hao, Shu-Hong; Sun, Yan; Hu, Chun-Mei; Ma, Zhi-Hua; Wang, Zhi Ming; Liu, Jie; Liu, Hong Bo; Ye, Ming; Zhang, Yu Fei; Yang, Dong Sheng; Shi, Guang

    2015-01-01

    Background. This meta-analysis investigated the association between functional COX-2 gene polymorphisms and the risk of oral cancer. Methods. Several electronic databases were searched for published studies using combinations of keywords related to COX-2 gene polymorphisms and oral cancer. After selection of relevant studies, following strict inclusion and exclusion criteria, data was performed using STATA 12.0 software. Results. We retrieved 83 studies from database search using specific search terms. After multiple rounds of selection and elimination, 7 studies were finally identified as suitable to be included in our present meta-analysis, based on their relevance and data integrity. These 7 studies contained a combined total of 2,296 oral cancer patients and 3,647 healthy controls. Our findings demonstrated that +837 T > C (rs5275) polymorphism in COX-2 showed statistically significant differences in gene frequencies in case and control groups in allele model and dominant model. Similar results were obtained with COX-2 gene polymorphism 765 G > C (rs20417). On the other hand, 1195 A > G (rs689466) polymorphism in COX-2 did not confer susceptibility to oral cancers. Conclusion. Based on our results, COX-2 gene polymorphisms, +837 T > C (rs5275) and −765G > C (rs20417), showed clear links with oral cancer susceptibility, and the 1195A > G (rs689466) polymorphism did not show such a correlation. PMID:25977924

  9. [COX-2 regulation of prostaglandins in synaptic signaling].

    PubMed

    Yang, Hong-Wei

    2009-10-01

    Cyclooxygenase-2 (COX-2) is a rate-limiting enzyme converting arachidonic acid to prostaglandins (PGs), which is a key messenger in traumatic brain injury- and ischemia-induced neuronal damage and in neuroinflammation. COX-2 is implicated in the pathogeneses of neurodegenerative diseases. Growing evidence implies that the contribution of COX-2 to neuropathology is associated with its involvement in synaptic alteration. Elevation or inhibition of COX-2 has been shown to enhance or suppress excitatory glutamatergic neurotransmission and long-term potentiation (LTP). These events are mainly mediated via PGE2, the predominant reaction product of COX-2, and the PGE2 subtype 2 receptor (EP2). Thus, elucidation of COX-2 in synaptic signaling may provide a mechanistic basis for designing new drugs aimed at preventing, treating or alleviating neuroinflammation-associated neurological disorders.

  10. Investigating the selectivity of metalloenzyme inhibitors.

    PubMed

    Day, Joshua A; Cohen, Seth M

    2013-10-24

    The inhibitory activity of a broad group of known metalloenzyme inhibitors against a panel of metalloenzymes was evaluated. Clinically approved inhibitors were selected as well as several other reported metalloprotein inhibitors in order to represent a broad range of metal binding groups (MBGs), including hydroxamic acid, carboxylate, hydroxypyridinonate, thiol, and N-hydroxyurea functional groups. A panel of metalloenzymes, including carbonic anhydrase (hCAII), several matrix metalloproteinases (MMPs), angiotensin converting enzyme (ACE), histone deacetylase (HDAC-2), and tyrosinase (TY), was selected based on their clinical importance for a range of pathologies. In addition, each inhibitor was evaluated for its ability to remove Fe(3+) from holo-transferrin to gauge the ability of the inhibitors to access Fe(3+) from a primary transport protein. The results show that the metalloenzyme inhibitors are quite selective for their intended targets, suggesting that despite their ability to bind metal ions, metalloprotein inhibitors are not prone to widespread off-target enzyme inhibition activity.

  11. Transcription factor Ets-1 inhibits glucose-stimulated insulin secretion of pancreatic β-cells partly through up-regulation of COX-2 gene expression.

    PubMed

    Zhang, Xiong-Fei; Zhu, Yi; Liang, Wen-Biao; Zhang, Jing-Jing

    2014-08-01

    Increased cyclooxygenase-2 (COX-2) expression is associated with pancreatic β-cell dysfunction. We previously demonstrated that the transcription factor Ets-1 significantly up-regulated COX-2 gene promoter activity. In this report, we used the pancreatic β-cell line INS-1 and isolated rat islets to investigate whether Ets-1 could induce β-cell dysfunction through up-regulating COX-2 gene expression. We investigated the effects of ETS-1 overexpression and the effects of ETS-1 RNA interference on endogenous COX-2 expression in INS-1 cells. We used site-directed mutagenesis and a dual luciferase reporter assay to study putative Ets-1 binding sites in the COX-2 promoter. The effect of ETS-1 1 overexpression on the insulin secretion function of INS-1 cells and rat islets and the potential reversal of these effects by a COX-2 inhibitor were determined in a glucose-stimulated insulin secretion (GSIS) assay. ETS-1 overexpression significantly induces endogenous COX-2 expression, but ETS-1 RNA interference has no effect on basal COX-2 expression in INS-1 cells. Ets-1 protein significantly increases COX-2 promoter activity through the binding site located in the -195/-186 region of the COX-2 promoter. ETS-1 overexpression significantly inhibited the GSIS function of INS-1 cells and islet cells and COX-2 inhibitor treatment partly reversed this effect. These findings indicated that ETS-1 overexpression induces β-cell dysfunction partly through up-regulation of COX-2 gene expression. Moreover, Ets-1, the transcriptional regulator of COX-2 expression, may be a potential target for the prevention of β-cell dysfunction mediated by COX-2.

  12. Immunohistochemical evaluation of COX-1 and COX-2 expression in keloid and hypertrophic scar.

    PubMed

    Abdou, Asmaa G; Maraee, Alaa H; Saif, Hala F Abd-Elsattar

    2014-04-01

    Both keloids (KLs) and hypertrophic scars (HSs) are considered as dermal fibroproliferative diseases that differ clinically and histopathologically. Although several factors have been postulated in the etiopathogenesis of these conditions, there has been growing evidence to suggest the role of COXs in the pathogenesis of abnormal wound healing because of the reduction of formation of KL and HS in patients using nonsteroidal anti-inflammatory drugs and a COX-2 inhibitor. The aim of the present work is to evaluate the pattern and localization of COX-1 and COX-2 expression in KL and HS compared with surgical scars. COX-1 and COX-2 were analyzed on skin biopsies of 30 patients who presented with KL (15) and HS (15) and 10 normal surgical scars (controls). Both COX-1 and COX-2 were expressed not only in dermal components (fibroblasts, inflammatory cells, and endothelial cells) but also in keratinocytes of the overlying epidermis in the different studied scar lesions. The percentage of COX-1 expression increased progressively from surgical scar (40%) to HS (53.3%) to KL (100%) with a statistically significant difference (P = 0.002). COX-2 was expressed in 100% of surgical scars, 73.3% of HS and 86.7% of KL with the absence of significant differences (P > 0.05). The significant difference in COX-1 expression between HS and KL may refer to the presence of different pathways for the emergence of these diseases. The expression of COX-2 in all scars (normal or abnormal) indicates its active role as an inflammatory mediator. Keratinocytes play an active role in induction of scarring by up-regulation of inflammatory mediators, such as COX-1 and COX-2.

  13. Anti-proliferative and apoptotic effects of etoricoxib, a selective COX-2 inhibitor, on 1,2-dimethylhydrazine dihydrochloride-induced colon carcinogenesis.

    PubMed

    Tanwar, Lalita; Piplani, Honit; Sanyal, Sn

    2010-01-01

    In the present study, we assessed effects of etoricoxib, a non-steroidal anti-inflammatory drug, on proliferation and apoptosis in 1,2-dimethylhydrazine dihydrochloride (DMH) induced colon lesion development. Male SD rats were divided into four groups: Group 1 controls receiving the vehicle treatment; Group 2 administered DMH weekly (30 mg/kg body weight, subcutaneously) alone; Group 3, DMH weekly plus etoricoxib (0.64 mg/kg body weight, orally) daily; and Group 4, etoricoxib alone. After six weeks of treatment, animals were sacrificed and colons were analysed for morphological and histopathological features. Well characterized pre-neoplastic aberrations such as multiple plaque lesions, hyperplasia and dysplasia were found in the DMH treated group whereas these features were reduced with co-administration of etoricoxib. To study apoptosis, colonocytes were isolated by metal chelation from colonic sacs and studied by fluorescent staining and further confirmed by DNA fragmentation. The DMH treated animals had fewer apoptotic nuclei as compared to the controls, but numbers were higher with DMH+etoricoxib as well as etoricoxib alone. Expression of proliferative cell nuclear antigen (PCNA), assessed by Western blot analysis and immunohistochemistry, was found to be elevated by DMH treatment group and again reduced by etoricoxib. Results for bromodeoxyuridine incorporation (BrdU) were in agreement. It may be concluded that the drug, etoricoxib, has the potential to act as an anti-apoptotic and anti- proliferative agent in the colon.

  14. COX2 Inhibition Reduces Aortic Valve Calcification In Vivo

    PubMed Central

    Wirrig, Elaine E.; Gomez, M. Victoria; Hinton, Robert B.; Yutzey, Katherine E.

    2016-01-01

    Objective Calcific aortic valve disease (CAVD) is a significant cause of morbidity and mortality, which affects approximately 1% of the US population and is characterized by calcific nodule formation and stenosis of the valve. Klotho-deficient mice were used to study the molecular mechanisms of CAVD as they develop robust aortic valve (AoV) calcification. Through microarray analysis of AoV tissues from klotho-deficient and wild type mice, increased expression of the gene encoding cyclooxygenase 2/COX2 (Ptgs2) was found. COX2 activity contributes to bone differentiation and homeostasis, thus the contribution of COX2 activity to AoV calcification was assessed. Approach and Results In klotho-deficient mice, COX2 expression is increased throughout regions of valve calcification and is induced in the valvular interstitial cells (VICs) prior to calcification formation. Similarly, COX2 expression is increased in human diseased AoVs. Treatment of cultured porcine aortic VICs with osteogenic media induces bone marker gene expression and calcification in vitro, which is blocked by inhibition of COX2 activity. In vivo, genetic loss of function of COX2 cyclooxygenase activity partially rescues AoV calcification in klotho-deficient mice. Moreover, pharmacologic inhibition of COX2 activity in klotho-deficient mice via celecoxib-containing diet reduces AoV calcification and blocks osteogenic gene expression. Conclusions COX2 expression is upregulated in CAVD and its activity contributes to osteogenic gene induction and valve calcification in vitro and in vivo. PMID:25722432

  15. Lovastatin lactone elicits human lung cancer cell apoptosis via a COX-2/PPARγ-dependent pathway

    PubMed Central

    Ramer, Robert; Mittag, Nadine; Hinz, Burkhard

    2016-01-01

    Statins (3-hydroxy-3-methylglutaryl coenzyme A [HMG-CoA] reductase inhibitors) are well-established agents to treat hyperlipidemic states. Experimental and epidemiological evidence further implies an anticancer effect of these substances. This study investigates the mechanism underlying human lung cancer cell death by lovastatin and the role of the prostaglandin (PG)-synthesizing enzyme cyclooxygenase-2 (COX-2) in this process. In A549 and H358 lung carcinoma cells the lipophilic prodrug lovastatin lactone led to a concentration-dependent decrease of viability and induction of DNA fragmentation, whereas its HMG-CoA-inhibitory, ring-open acid form was inactive in this respect. Apoptotic cell death by lovastatin was accompanied by high intracellular levels of the lactone form, by upregulation of COX-2 mRNA and protein, as well as by increased formation of peroxisome proliferator-activated receptor γ (PPARγ)-activating PGD2 and 15-deoxy-Δ12,14-PGJ2. Cells were significantly less sensitive to lovastatin-induced apoptotic cell death, when the expression or activity of COX-2 was suppressed by siRNA or by the COX-2 inhibitor NS-398. Apoptosis by lovastatin was likewise reversed by the PPARγ antagonist GW9662. Fluorescence microscopy analyses revealed a lovastatin-induced cytosol-to-nucleus translocation of PPARγ that was inhibited by NS-398. Collectively, this study demonstrates COX-2 induction and subsequent COX-2-dependent activation of PPARγ as a hitherto unknown mechanism by which lovastatin lactone induces human lung cancer cell death. PMID:26863638

  16. Molecular docking studies of withanolides against Cox-2 enzyme.

    PubMed

    Prabhakaran, Yogeswaran; Dinakaran, Sathis Kumar; Macharala, Sravan Prasad; Ghosh, Somsubhra; Karanam, Sridevi Ranjitha; Kanthasamy, Naveena; Avasarala, Harani

    2012-07-01

    Withaniasomnifera (Ashwaganda) belonging to the family solanaceae is the subject of our present study. Withanoloides which are the major chemical constituents have been proved of interest because of their structural variations in the hybrids of different races. Docking is the process which brings the two structures together. In the present study we focus the extensive use of tool and graphical software for the identification of the binding energy of selected Withanolides like Withaferin -A, Withanolide-D from Withaniasomnifera and to screen the phytoconstituents that will dock/bind to the active sites of COX-2 enzyme. The relief from the symptoms of inflammation and pain can be by the Pharmacological inhibition of COX which involves the prediction of potential ligand for the treatment of inflammation. The energy value of docking between the target and the phytoconstituents under investigation and comparison with Diclofenac sodium was taken into consideration for coming into conclusion regarding the best pose and the binding ability.

  17. Cyclooxygenase-1-Selective Inhibitors Based on the (E)-2′-Des-methyl-sulindac Sulfide Scaffold

    PubMed Central

    2012-01-01

    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. PMID:22263894

  18. TCDD‑induced chick cardiotoxicity is abolished by a selective cyclooxygenase‑2 (COX‑2) inhibitor NS398.

    PubMed

    Fujisawa, Nozomi; Nakayama, Shouta M M; Ikenaka, Yoshinori; Ishizuka, Mayumi

    2014-09-01

    Halogenated aromatic hydrocarbons, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are known to cause severe heart defects in avian species. However, the mechanism of TCDD-induced chick cardiovascular toxicity is unclear. In this study, we investigated cyclooxygenase-2 (COX-2) as a possible mechanism of TCDD-induced cardiotoxicity. Fertile chicken eggs were injected with TCDD and a COX-2 selective inhibitor, NS398, and we investigated chick heart failure on day 10. We found that the chick heart to body weight ratio and atrial natriuretic factor mRNA expression were increased, but this increase was abolished with treatment of NS398. In addition, the morphological abnormality of an enlarged ventricle resulting from TCDD exposure was also abolished with co-treatment of TCDD and NS398. Our results suggested that TCDD-induced chick heart defects are mediated via the nongenomic pathway and that they do not require the genomic pathway.

  19. Clinical significance of COX-2, GLUT-1 and VEGF expressions in endometrial cancer tissues

    PubMed Central

    Ma, Xiaoping; Hui, Yuzuo; Lin, Li; Wu, Yu; Zhang, Xian; Liu, Peishu

    2015-01-01

    Objective: To analyze the clinical significance of COX-2, GLUT-1 and VEGF expressions in endometrial cancer tissues. Methods: One hundred and eight tissue samples from the patients with endometrial cancer enrolled in our hospital from August 2011 to July 2014 were selected, including 60 normal tissue samples (normal group), 60 neoplastic tissue samples (neoplastic group) and 60 cancer tissue samples (cancer group). All the samples were subjected to immunohistochemical assay to detect the expressions of COX-2, GLUT-1 and VEGF. The clinical data were also investigated for correlation analysis. Results: The positive rates of COX-2 in normal group, neoplastic group and cancer groups were 3.3%, 21.7% and 55.0% respectively. The positive rates of GLUT-1 in normal group, neoplastic group and cancer groups were 3.3%, 25.0% and 70.0% respectively. The positive rates of VEGF in normal group, neoplastic group and cancer groups were 1.7%, 23.3% and 63.3% respectively. With increasing stage of such cancer, decreasing degree of differentiation and lymphatic metastasis, the positive expression rates of COX-2, GLUT-1 and VEGF proteins were raised significantly (P<0.05). Spearman’s correlation analysis showed that the expressions of COX-2 and GLUT-1 (r=0.207, P<0.05), COX-2 and VEGF (r=0.243, P<0.05), as well as GLUT-1 and VEGF (r=0.758, P<0.05) were positively correlated. Conclusion: COX-2, GLUT-1 and VEGF were highly prominent in endometrial cancer, especially in the patients with low degree of differentiation, late stage and metastasis. They functioned synergistically in the onset and progression of this cancer. PMID:26101475

  20. Selective serotonin reuptake inhibitor exposure.

    PubMed

    Fitzgerald, Kevin T; Bronstein, Alvin C

    2013-02-01

    Many antidepressants inhibit serotonin or norepinephrine reuptake or both to achieve their clinical effect. The selective serotonin reuptake inhibitor class of antidepressants (SSRIs) includes citalopram, escitalopram (active enantiomer of citalopram), fluoxetine, fluvoxamine, paroxetine, and sertraline. The SSRIs are as effective as tricyclic antidepressants in treatment of major depression with less significant side effects. As a result, they have become the largest class of medications prescribed to humans for depression. They are also used to treat obsessive-compulsive disorder, panic disorders, alcoholism, obesity, migraines, and chronic pain. An SSRI (fluoxetine) has been approved for veterinary use in treatment of canine separation anxiety. SSRIs act specifically on synaptic serotonin concentrations by blocking its reuptake in the presynapse and increasing levels in the presynaptic membrane. Clinical signs of SSRI overdose result from excessive amounts of serotonin in the central nervous system. These signs include nausea, vomiting, mydriasis, hypersalivation, and hyperthermia. Clinical signs are dose dependent and higher dosages may result in the serotonin syndrome that manifests itself as ataxia, tremors, muscle rigidity, hyperthermia, diarrhea, and seizures. Current studies reveal no increase in appearance of any specific clinical signs of serotonin toxicity with regard to any SSRI medication. In people, citalopram has been reported to have an increased risk of electrocardiographic abnormalities. Diagnosis of SSRI poisoning is based on history, clinical signs, and response to therapy. No single clinical test is currently available to confirm SSRI toxicosis. The goals of treatment in this intoxication are to support the animal, prevent further absorption of the drug, support the central nervous system, control hyperthermia, and halt any seizure activity. The relative safety of the SSRIs in overdose despite the occurrence of serotonin syndrome makes them

  1. COX-2 inhibition affects growth rate of Chlamydia muridarum within epithelial cells.

    PubMed

    Liu, Wei; Dubinett, Steven; Patterson, Simie Lavern A; Kelly, Kathleen A

    2006-02-01

    Chlamydiae alter apoptosis of host target cells, which regulates their growth. Cyclooxygenase-2 (COX-2), the rate-limiting enzyme for prostaglandin E2 (PGE2) production, modulates epithelial cell survival. We addressed whether endogenous PGE2 alters chlamydial growth or apoptosis of epithelial cells infected with Chlamydia muridarum. PGE2 is secreted by infected host cells in the genital tract (GT). Using immunohistochemical techniques, we found that COX-2 enzyme was localized to epithelial cells in the GT in vivo. Pellets of the COX-2 enzyme inhibitor, NS-398, and placebo were implanted in mice subcutaneously and released a constant amount of these chemicals throughout the infection. NS-398-treated mice were found to exhibit 10-fold lower bacterial load than the placebo group on day 3 post infection, suggesting disruption of the chlamydial developmental cycle. To prove this, the human lung adenocarcinoma cell line A549 was then infected with different MOIs of C. muridarum in the presence of multiple concentrations of NS-398 in vitro. There was no difference in inclusion forming units (IFUs) between NS-389-treated and untreated cells. We also found no alterations in C. muridarum IFUs in A549 cells transfected with a 2.0 kb cDNA fragment of human COX-2 cloned in the sense (S) or anti-sense (AS) orientation. However, the inclusion size was reduced and the number of EB was significantly diminished during reinfection in AS-transfected cells. In addition, the absence of COX-2 did not significantly modify apoptosis in infected cells. In total, COX-2 deficiency reduces the infectious burden in vivo and may modulate transmission of the organism.

  2. Overexpression of cyclooxygenase-2 in rat oral cancers and prevention of oral carcinogenesis in rats by selective and nonselective COX inhibitors.

    PubMed

    McCormick, David L; Phillips, Jonathan M; Horn, Thomas L; Johnson, William D; Steele, Vernon E; Lubet, Ronald A

    2010-01-01

    Oral squamous cell carcinomas induced in rats by 4-nitroquinoline-1-oxide (NQO) show substantial overexpression of cyclooxygenase-2 (COX-2) when compared with adjacent phenotypically normal oral tissues. By contrast, neither 5-lipoxygenase (LOX) nor 12-LOX is overexpressed in rat oral cancers. Two chemoprevention studies were done to test the resulting hypothesis that COX-2 is a useful target for oral cancer chemoprevention in the rat. In both studies, male F344 rats received drinking water exposure to NQO (20 ppm) for 10 weeks, followed by administration of chemopreventive agents from week 10 until study termination at week 26. In the first study, groups of rats were fed basal diet (control), or basal diet supplemented with the selective COX-2 inhibitor celecoxib (500 or 1,500 mg/kg diet), the nonselective COX inhibitor piroxicam (50 or 150 mg/kg diet), or the 5-LOX inhibitor zileuton (2,000 mg/kg diet). In the second study, rats were fed basal diet (control) or basal diet supplemented with nitric oxide-naproxen (180 or 90 mg/kg diet), a nonselective COX inhibitor that shows reduced gastrointestinal toxicity. When compared with dietary controls, celecoxib decreased oral cancer incidence, cancer invasion score, and cancer-related mortality. Piroxicam decreased cancer-related mortality and cancer invasion score, whereas nitric oxide-naproxen decreased oral cancer incidence and cancer invasion score. By contrast, zileuton showed no chemopreventive activity by any parameter assessed. These data show that both selective and nonselective inhibitors of COX-2 can prevent NQO-induced oral carcinogenesis in rats. The chemopreventive activity of COX inhibitors may be linked to overexpression of their enzymatic target in incipient oral neoplasms.

  3. Mitophagy inhibits proliferation by decreasing cyclooxygenase-2 (COX-2) in arsenic trioxide-treated HepG2 cells.

    PubMed

    Niu, Zhidan; Zhang, Wenya; Gu, Xueyan; Zhang, Xiaoning; Qi, Yongmei; Zhang, Yingmei

    2016-07-01

    Mitochondrial damage can trigger mitophagy and eventually suppress proliferation. However, the effect of mitophagy on proliferation remains unclear. In this study, HepG2 cells were used to assess mitophagy and proliferation arrest in response to As2O3 exposure. The stimulatory effect of As2O3 on mitophagy was investigated by assessing morphology (mitophagosome and mitolysosome) and relevant proteins (PINK1, LC3 II/I, and COX IV). Additionally, the relationship of mitophagy and proliferation was explored through the use of mitophagy inhibitors (CsA, Mdivi-1). Interestingly, the inhibition of mitophagy rescued proliferation arrest by restoring COX-2 protein level and countered the elimination of mitochondria-located COX-2 and up-regulated the COX-2 mRNA level. Taken together, our findings indicated that mitophagy can be induced and can inhibit proliferation by reducing COX-2 in HepG2 cells during As2O3 treatment.

  4. Role of COX-2 in cough reflex sensitivity to inhaled capsaicin in patients with sinobronchial syndrome

    PubMed Central

    2010-01-01

    Background Sinobronchial syndrome is a cause of chronic productive cough. Inflammatory mediators are involved in the pathophysiology of chronic productive cough. Accumulating evidences indicate that cyclooxygenase (COX)-2, one of the inducible isoforms of COX, is a key element in the pathophysiological process of a number of inflammatory disorders. However, little is known about the role of COX-2 in chronic productive cough in patients with sinobronchial syndrome known as neutrophilic bronchial inflammation. Methods The effect of etodolac, a potent COX-2 inhibitor, on cough response to inhaled capsaicin was examined in 15 patients with sinobronchial syndrome in a randomized, placebo-controlled cross-over study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough reflex sensitivity. Results The cough threshold was significantly (p < 0.03) increased after two-week treatment with etodolac (200 mg twice a day orally) compared with placebo [37.5 (GSEM 1.3) vs. 27.2 (GSEM 1.3) μM]. Conclusions These findings indicate that COX-2 may be a possible modulator augmenting airway cough reflex sensitivity in patients with sinobronchial syndrome. PMID:20696045

  5. A Novel Selective Prostaglandin E2 Synthesis Inhibitor Relieves Pyrexia and Chronic Inflammation in Rats.

    PubMed

    Sugita, Ryusuke; Kuwabara, Harumi; Sugimoto, Kotaro; Kubota, Kazufumi; Imamura, Yuichiro; Kiho, Toshihiro; Tengeiji, Atsushi; Kawakami, Katsuhiro; Shimada, Kohei

    2016-04-01

    Prostaglandin E2 (PGE2) is a terminal prostaglandin in the cyclooxygenase (COX) pathway. Inhibition of PGE2 production may relieve inflammatory symptoms such as fever, arthritis, and inflammatory pain. We report here the profile of a novel selective PGE2 synthesis inhibitor, compound A [N-[(1S,3S)-3-carbamoylcyclohexyl]-1-(6-methyl-3-phenylquinolin-2-yl)piperidine-4-carboxamide], in animal models of pyrexia and inflammation. The compound selectively suppressed the synthesis of PGE2 in human alveolar adenocarcinoma cell line A549 cells and rat macrophages. In the lipopolysaccharide-induced pyrexia model, this compound selectively reduced PGE2 production in cerebrospinal fluid and showed an anti-pyretic effect. In the adjuvant-induced arthritis model, compound A therapeutically decreased foot swelling in the established arthritis. Our data demonstrates that selective suppression of PGE2 synthesis shows anti-pyretic and anti-inflammatory effects, suggesting that selective PGE2 synthesis inhibitors can be applied as an alternative treatment to nonsteroidal, anti-inflammatory drugs (NSAIDs) or COX-2-selective inhibitors.

  6. Interactions between inducible isoforms of nitric oxide synthase and cyclo-oxygenase in vivo: investigations using the selective inhibitors, 1400W and celecoxib

    PubMed Central

    Hamilton, Lorna C; Warner, Timothy D

    1998-01-01

    Exposure of tissues to endotoxin (LPS) and/or cytokines leads to the induction of both inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2). It has previously been reported that there is `cross-talk' between these two systems. However, such previous studies have been limited by the availability of highly selective inhibitors. Here we have investigated the interactions between iNOS and COX-2 in vivo using 1400W, an iNOS-selective inhibitor, and celecoxib, a COX-2-selective inhibitor.Infusion of LPS to rats for 6 h caused a time-dependent increase in the plasma concentrations of 6 keto-prostaglandin F1α (6 keto-PGF1α) and nitrite/nitrate (NO2/NO3), consistent with the induction of iNOS and COX-2. Bolus injection of arachidonic acid (AA) at t=6 h resulted in a further increase of circulating levels of 6 keto-PGF1α in LPS-treated animals.Treatment of rats with 1400W or the non-selective NOS inhibitor NG-monomethyl-L-arginine (L-NMMA) inhibited the increase in plasma NO2/NO3 but were both without effect on the plasma concentration of 6 keto-PGF1α before or after AA.Treatment with the non-steroidal anti-inflammatory drugs (NSAIDs), A771726 or diclofenac, or with celecoxib significantly reduced the increase in circulating 6 keto-PGF1α caused by LPS, and the large increase in 6 keto-PGF1α following injection of AA. None of the COX inhibitors affected the increase in plasma NO2/NO3. Dexamethasone, however, significantly inhibited both the increase in 6 keto-PGF1α and the increase in NO2/NO3.In conclusion, the use of selective inhibitors does not support the concept of cross talk in vivo between iNOS and COX-2. PMID:9786506

  7. Nimesulide, a cyclooxygenase-2 selective inhibitor, suppresses obesity-related non-alcoholic fatty liver disease and hepatic insulin resistance through the regulation of peroxisome proliferator-activated receptor γ

    PubMed Central

    Tsujimoto, Shunsuke; Kishina, Manabu; Koda, Masahiko; Yamamoto, Yasutaka; Tanaka, Kohei; Harada, Yusuke; Yoshida, Akio; Hisatome, Ichiro

    2016-01-01

    Cyclooxygenase (COX)-2 selective inhibitors suppress non-alcoholic fatty liver disease (NAFLD); however, the precise mechanism of action remains unknown. The aim of this study was to examine how the COX-2 selective inhibitor nimesulide suppresses NAFLD in a murine model of high-fat diet (HFD)-induced obesity. Mice were fed either a normal chow diet (NC), an HFD, or HFD plus nimesulide (HFD-nime) for 12 weeks. Body weight, hepatic COX-2 mRNA expression and triglyceride accumulation were significantly increased in the HFD group. Triglyceride accumulation was suppressed in the HFD-nime group. The mRNA expression of hepatic peroxisome proliferator-activated receptor γ (PPARγ) and the natural PPARγ agonist 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) were significantly increased in the HFD group and significantly suppressed in the HFD-nime group. Glucose metabolism was impaired in the HFD group compared with the NC group, and it was significantly improved in the HFD-nime group. In addition, the plasma insulin levels in the HFD group were increased compared with those in the NC group, and were decreased in the HFD-nime group. These results indicate that HFD-induced NAFLD is mediated by the increased hepatic expression of COX-2. We suggest that the production of 15d-PGJ2, which is mediated by COX-2, induces NAFLD and hepatic insulin resistance by activating PPARγ. Furthermore, the mRNA expression of tissue inhibitor of metalloproteinases-1 (TIMP-1), procollagen-1 and monocyte chemoattractant protein-1 (MCP-1), as well as the number of F4/80-positive hepatic (Kupffer) cells, were significantly increased in the HFD group compared with the NC group, and they were reduced by nimesulide. In conclusion, COX-2 may emerge as a molecular target for preventing the development of NAFLD and insulin resistance in diet-related obesity. PMID:27431935

  8. Salt supplementation ameliorates developmental kidney defects in COX-2-/- mice.

    PubMed

    Slattery, Patrick; Frölich, Stefanie; Goren, Itamar; Nüsing, Rolf Michael

    2017-03-08

    Deficiency of cyclooxygenase-2 (COX-2) activity in the early postnatal time course causes impairment of kidney development leading to kidney insufficiency. We hypothesize that impaired NaCl reabsorption during the first days of life is a substantial cause for nephrogenic defects observed in COX-2-/- mice and that salt supplementation corrects these defects. Daily injections of 0.8 mg/g/d NaCl for the first 10 days after birth ameliorated impaired kidney development in COX-2-/- pups resulting in an increase in glomerular size and reduction of immature superficial glomeruli. However, impaired renal subcortical growth was not corrected. Increasing renal tubular flow by volume load or injections of KCl did not relieve the renal histomorphological damage. Administration of torsemide and spironolacton also affected nephrogenesis resulting in diminished glomeruli and cortical thinning. Treatment of COX-2-/- pups with NaCl/DOCA caused a stronger mitigation of glomerular size and also induced a slight but significant growth of cortical tissue mass. After birth renal mRNA expression of NHE3, NKCC2, ROMK, NCCT, ENaC, and Na+/K+-ATPase increased relative to day P2 in wild type mice. However, in COX-2-/- mice a significantly lower expression was observed for NCCT, while DOCA/NaCl treatment significantly increased NHE3 and ROMK expression. Regarding long-term effects of postnatal NaCl/DOCA injections improved kidney function with normalization of pathologically enhanced creatinine and urea plasma levels and albumin excretion was observed. In summary we present evidence that a salt supplementation during the COX-2 dependent time frame of nephrogenesis partly reverses renal morphological defects in COX-2-/- mice and improves kidney function.

  9. Celecoxib offsets the negative renal influences of cyclosporine via modulation of the TGF-β1/IL-2/COX-2/endothelin ET{sub B} receptor cascade

    SciTech Connect

    El-Gowelli, Hanan M.; Helmy, Maged W.; Ali, Rabab M.; El-Mas, Mahmoud M.

    2014-03-01

    Endothelin (ET) signaling provokes nephrotoxicity induced by the immunosuppressant drug cyclosporine A (CSA). We tested the hypotheses that (i): celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, counterbalances renal derangements caused by CSA in rats and (ii) the COX-2/endothelin ET{sub B} receptor signaling mediates the CSA-celecoxib interaction. Ten-day treatment with CSA (20 mg/kg/day) significantly increased biochemical indices of renal function (serum urea, creatinine), inflammation (interleukin-2, IL-2) and fibrosis (transforming growth factor-β{sub 1}, TGF-β{sub 1}). Histologically, CSA caused renal tubular atrophy along with interstitial fibrosis. These detrimental renal effects of CSA were largely reduced in rats treated concurrently with celecoxib (10 mg/kg/day). We also report that cortical glomerular and medullary tubular protein expressions of COX-2 and ET{sub B} receptors were reduced by CSA and restored to near-control values in rats treated simultaneously with celecoxib. The importance of ET{sub B} receptors in renal control and in the CSA-celecoxib interaction was further verified by the findings (i) most of the adverse biochemical, inflammatory, and histopathological profiles of CSA were replicated in rats treated with the endothelin ET{sub B} receptor antagonist BQ788 (0.1 mg/kg/day, 10 days), and (ii) the BQ788 effects, like those of CSA, were alleviated in rats treated concurrently with celecoxib. Together, the data suggest that the facilitation of the interplay between the TGF-β1/IL-2/COX-2 pathway and the endothelin ET{sub B} receptors constitutes the cellular mechanism by which celecoxib ameliorates the nephrotoxic manifestations of CSA in rats. - Highlights: • Celecoxib abolishes nephrotoxic manifestations of CSA in rats. • Blockade of ETB receptors by BQ788 mimicked the nephrotoxic effects of CSA. • CSA or BQ788 reduces renal protein expression of COX-2 and endothelin ETB receptors. • Enhanced TGFβ1/IL-2/COX2/ETB

  10. Inhibitory effect of etodolac, a selective cyclooxygenase-2 inhibitor, on stomach carcinogenesis in Helicobacter pylori-infected Mongolian gerbils

    SciTech Connect

    Magari, Hirohito; Shimizu, Yasuhito; Inada, Ken-ichi; Enomoto, Shotaro; Tomeki, Tatsuji; Yanaoka, Kimihiko; Tamai, Hideyuki; Arii, Kenji; Nakata, Hiroya; Oka, Masashi; Utsunomiya, Hirotoshi; Tsutsumi, Yutaka; Tsukamoto, Tetsuya; Tatematsu, Masae; Ichinose, Masao E-mail: ichinose@wakayama-med.ac.jp

    2005-08-26

    The effect of the selective COX-2 inhibitor, etodolac, on Helicobacter pylori (Hp)-associated stomach carcinogenesis was investigated in Mongolian gerbils (MGs). Hp-infected MGs were fed for 23 weeks with drinking water containing 10 ppm N-methyl-N-nitrosourea. They were then switched to distilled water and placed on a diet containing 5-30 mg/kg/day etodolac for 30 weeks. We found that etodolac dose-dependently inhibited the development of gastric cancer, and no cancer was detected at a dose of 30 mg/kg/day. Etodolac did not affect the extent of inflammatory cell infiltration or oxidative DNA damage, but it significantly inhibited mucosal cell proliferation and dose-dependently repressed the development of intestinal metaplasia in the stomachs of Hp-infected MGs. These results suggest that COX-2 is a key molecule in inflammation-mediated stomach carcinogenesis and that chemoprevention of stomach cancer should be possible by controlling COX-2 expression or activity.

  11. COX-2 expression is correlated with VEGF-C, lymphangiogenesis and lymph node metastasis in human cervical cancer.

    PubMed

    Liu, Huidong; Xiao, Jianbing; Yang, Yanmei; Liu, Yan; Ma, Ruijin; Li, Yuhang; Deng, Fengchun; Zhang, Yafang

    2011-09-01

    Lymphangiogenesis has been shown to promote lymph node metastasis in cancers, making it an important target in cancer therapy. Vascular endothelial growth factor (VEGF)-C is upregulated in various tumors/cancers and is one of the most potent growth factors for inducing lymphangiogenesis and promoting lymph node metastasis (LNM). Likewise, cyclooxygenase (COX)-2 plays major roles in carcinogenesis, tumor growth and metastasis via multiple mechanisms including inactivation of host antitumor immunity and promotion of tumor cell migration, tumor cell invasiveness and tumor-associated angiogenesis and lymphangiogenesis. We previously demonstrated an association between COX-2 and VEGF-C in an in vitro model of lung cancer. However, little is known about the regulation of VEGF-C by COX-2 in cervical cancer. In this study, we measured the COX-2 and VEGF-C expressions by immunohistochemistry in 23 LNM-positive and 20 LNM-negative cervical cancer specimens. We then examined the correlations among the expressions and the lymphatic microvessel density (LMVD) and ultrastructural changes to the lymphatic vessel walls by enzyme histochemical staining and electron microscopy. In addition, we used the HeLa cervical cancer cell line to explore the in vitro regulation of VEGF-C by COX-2 and its metabolite, PGE(2), using siRNA-mediated gene silencing and EP receptor blockade. The LNM-positive specimens exhibited significantly higher VEGF-C expression, COX-2 expression and LMVD than the LNM-negative specimens. Furthermore, there were strong correlations between the levels of COX-2 expression and the levels of VEGF-C expression and secretion and a significant positive association between the LMVD and LNM. siRNA-mediated knockdown of COX-2 expression inhibited VEGF-C mRNA expression while EP1 and EP4 receptor antagonists reduced the VEGF-C protein level and tyrosine phosphorylation of Src kinase. Moreover, inhibition of Src kinase with the tyrosine kinase inhibitor PP1 attenuated VEGF

  12. Selective Phosphodiesterase 4B Inhibitors: A Review

    PubMed Central

    Azam, Mohammed Afzal; Tripuraneni, Naga Srinivas

    2014-01-01

    Abstract Phosphodiesterase 4B (PDE4B) is a member of the phosphodiesterase family of proteins that plays a critical role in regulating intracellular levels of cyclic adenosine monophosphate (cAMP) by controlling its rate of degradation. It has been demonstrated that this isoform is involved in the orchestra of events which includes inflammation, schizophrenia, cancers, chronic obstructive pulmonary disease, contractility of the myocardium, and psoriatic arthritis. Phosphodiesterase 4B has constituted an interesting target for drug development. In recent years, a number of PDE4B inhibitors have been developed for their use as therapeutic agents. In this review, an up-to-date status of the inhibitors investigated for the inhibition of PDE4B has been given so that this rich source of structural information of presently known PDE4B inhibitors could be helpful in generating a selective and potent inhibitor of PDE4B. PMID:25853062

  13. COX-2 Inhibition Reduces Brucella Bacterial Burden in Draining Lymph Nodes

    PubMed Central

    Gagnaire, Aurélie; Gorvel, Laurent; Papadopoulos, Alexia; Von Bargen, Kristine; Mège, Jean-Louis; Gorvel, Jean-Pierre

    2016-01-01

    Brucella is a Gram-negative facultative intracellular bacterium responsible for a chronic disease known as brucellosis, the most widespread re-emerging zoonosis worldwide. Establishment of a Th1-mediated immune response characterized by the production of IL-12 and IFNγ is essential to control the disease. Leukotrienes derived from arachidonic acid (AA) metabolism are known to negatively regulate a protective Th1 immune response against bacterial infections. Here, using genomics approaches we demonstrate that Brucella abortus strongly stimulates the prostaglandin (PG) pathway in dendritic cells (DC). We also show an induction of AA production by infected cells. This correlates with the expression of Ptgs2, a gene encoding the downstream cyclooxygenase-2 (COX-2) enzyme in infected DC. By comparing different infection routes (oral, intradermal, intranasal and conjunctival), we identified the intradermal inoculation route as the more potent in inducing Ptgs2 expression but also in inducing a local inflammatory response in the draining cervical lymph nodes (CLN). NS-398, a specific inhibitor of COX-2 enzymatic activity decreased B. melitensis burden in the CLN after intradermal infection. This effect was accompanied by a decrease of Il10 and a concomitant increase of Ifng expression. Altogether, these results suggest that Brucella has evolved to take advantage of the PG pathway in the harsh environment of the CLN in order to persist and subvert immune responses. This work also proposes that novel strategies to control brucellosis may include the use of COX-2 inhibitors. PMID:28018318

  14. Celecoxib offsets the negative renal influences of cyclosporine via modulation of the TGF-β1/IL-2/COX-2/endothelin ET(B) receptor cascade.

    PubMed

    El-Gowelli, Hanan M; Helmy, Maged W; Ali, Rabab M; El-Mas, Mahmoud M

    2014-03-01

    Endothelin (ET) signaling provokes nephrotoxicity induced by the immunosuppressant drug cyclosporine A (CSA). We tested the hypotheses that (i): celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, counterbalances renal derangements caused by CSA in rats and (ii) the COX-2/endothelin ET(B) receptor signaling mediates the CSA-celecoxib interaction. Ten-day treatment with CSA (20 mg/kg/day) significantly increased biochemical indices of renal function (serum urea, creatinine), inflammation (interleukin-2, IL-2) and fibrosis (transforming growth factor-β₁, TGF-β₁). Histologically, CSA caused renal tubular atrophy along with interstitial fibrosis. These detrimental renal effects of CSA were largely reduced in rats treated concurrently with celecoxib (10 mg/kg/day). We also report that cortical glomerular and medullary tubular protein expressions of COX-2 and ET(B) receptors were reduced by CSA and restored to near-control values in rats treated simultaneously with celecoxib. The importance of ET(B) receptors in renal control and in the CSA-celecoxib interaction was further verified by the findings (i) most of the adverse biochemical, inflammatory, and histopathological profiles of CSA were replicated in rats treated with the endothelin ETB receptor antagonist BQ788 (0.1 mg/kg/day, 10 days), and (ii) the BQ788 effects, like those of CSA, were alleviated in rats treated concurrently with celecoxib. Together, the data suggest that the facilitation of the interplay between the TGF-β1/IL-2/COX-2 pathway and the endothelin ET(B) receptors constitutes the cellular mechanism by which celecoxib ameliorates the nephrotoxic manifestations of CSA in rats.

  15. Inhibitors Selective for Mycobacterial Versus Human Proteasomes

    SciTech Connect

    Lin, G.; Li, D; Sorio de Carvalho, L; Deng, H; Tao, H; Vogt, G; Wu, K; Schneider, J; Chidawanyika, T; et. al.

    2009-01-01

    Many anti-infectives inhibit the synthesis of bacterial proteins, but none selectively inhibits their degradation. Most anti-infectives kill replicating pathogens, but few preferentially kill pathogens that have been forced into a non-replicating state by conditions in the host. To explore these alternative approaches we sought selective inhibitors of the proteasome of Mycobacterium tuberculosis. Given that the proteasome structure is extensively conserved, it is not surprising that inhibitors of all chemical classes tested have blocked both eukaryotic and prokaryotic proteasomes, and no inhibitor has proved substantially more potent on proteasomes of pathogens than of their hosts. Here we show that certain oxathiazol-2-one compounds kill non-replicating M.?tuberculosis and act as selective suicide-substrate inhibitors of the M.?tuberculosis proteasome by cyclocarbonylating its active site threonine. Major conformational changes protect the inhibitor-enzyme intermediate from hydrolysis, allowing formation of an oxazolidin-2-one and preventing regeneration of active protease. Residues outside the active site whose hydrogen bonds stabilize the critical loop before and after it moves are extensively non-conserved. This may account for the ability of oxathiazol-2-one compounds to inhibit the mycobacterial proteasome potently and irreversibly while largely sparing the human homologue.

  16. Urban particulate matter down-regulates filaggrin via COX2 expression/PGE2 production leading to skin barrier dysfunction

    PubMed Central

    Lee, Chiang-Wen; Lin, Zih-Chan; Hu, Stephen Chu-Sung; Chiang, Yao-Chang; Hsu, Lee-Fen; Lin, Yu-Ching; Lee, I-Ta; Tsai, Ming-Horng; Fang, Jia-You

    2016-01-01

    We explored the regulation of filaggrin, cyclooxygenase 2 (COX2) and prostaglandin E2 (PGE2) expression induced by urban particulate matter (PM) in human keratinocytes. In addition, we investigated the signaling pathways involved in PM-induced effects on COX2/PGE2 and filaggrin. PMs induced increases in COX2 expression and PGE2 production, and decreased filaggrin expression. These effects were attenuated by pretreatment with COX2 inhibitor and PGE2 receptor antagonist, or after transfection with siRNAs of the aryl hydrocarbon receptor (AhR), gp91phox and p47phox. Furthermore, PM-induced generation of reactive oxygen species (ROS) and NADPH oxidase activity was attenuated by pretreatment with an AhR antagonist (AhRI) or antioxidants. Moreover, Nox-dependent ROS generation led to phosphorylation of ERK1/2, p38, and JNK, which then activated the downstream molecules NF-κB and AP-1, respectively. In vivo studies in PMs-treated mice showed that AhRI and apocynin (a Nox2 inhibitor) had anti-inflammatory effects by decreasing COX2 and increasing filaggrin expression. Our results reveal for the first time that PMs-induced ROS generation is mediated through the AhR/p47 phox/NADPH oxidase pathway, which in turn activates ERK1/2, p38/NF-κB and JNK/AP-1, and which ultimately induces COX2 expression and filaggrin downregulation. Up-regulated expression of COX2 and production of PGE2 may lead to impairment of skin barrier function. PMID:27313009

  17. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis

    PubMed Central

    Kirkby, Nicholas S.; Tesfai, Abel; Ahmetaj-Shala, Blerina; Gashaw, Hime H.; Sampaio, Walkyria; Etelvino, Gisele; Leão, Nádia Miricéia; Santos, Robson A.; Mitchell, Jane A.

    2016-01-01

    Nonsteroidal antiinflammatory drugs, including ibuprofen, are among the most commonly used medications and produce their antiinflammatory effects by blocking cyclooxygenase (COX)-2. Their use is associated with increased risk of heart attacks caused by blocking COX-2 in the vasculature and/or kidney, with our recent work implicating the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), a cardiotoxic hormone whose effects can be prevented by l-arginine. The ibuprofen salt ibuprofen arginate (Spididol) was created to increase solubility but we suggest that it could also augment the NO pathway through codelivery of arginine. Here we investigated the idea that ibuprofen arginate can act to simultaneously inhibit COX-2 and preserve the NO pathway. Ibuprofen arginate functioned similarly to ibuprofen sodium for inhibition of mouse/human COX-2, but only ibuprofen arginate served as a substrate for NOS. Ibuprofen arginate but not ibuprofen sodium also reversed the inhibitory effects of ADMA and NG-nitro-l-arginine methyl ester on inducible NOS (macrophages) and endothelial NOS in vitro (aorta) and in vivo (blood pressure). These observations show that ibuprofen arginate provides, in one preparation, a COX-2 inhibitor and NOS substrate that could act to negate the harmful cardiovascular consequences mediated by blocking renal COX-2 and increased ADMA. While remarkably simple, our findings are potentially game-changing in the nonsteroidal antiinflammatory drug arena.—Kirkby, N. S., Tesfai, A., Ahmetaj-Shala, B., Gashaw, H. H., Sampaio, W., Etelvino, G., Leão, N. M., Santos, R. A., Mitchell, J. A. Ibuprofen arginate retains eNOS substrate activity and reverses endothelial dysfunction: implications for the COX-2/ADMA axis. PMID:27601438

  18. Urban particulate matter down-regulates filaggrin via COX2 expression/PGE2 production leading to skin barrier dysfunction.

    PubMed

    Lee, Chiang-Wen; Lin, Zih-Chan; Hu, Stephen Chu-Sung; Chiang, Yao-Chang; Hsu, Lee-Fen; Lin, Yu-Ching; Lee, I-Ta; Tsai, Ming-Horng; Fang, Jia-You

    2016-06-17

    We explored the regulation of filaggrin, cyclooxygenase 2 (COX2) and prostaglandin E2 (PGE2) expression induced by urban particulate matter (PM) in human keratinocytes. In addition, we investigated the signaling pathways involved in PM-induced effects on COX2/PGE2 and filaggrin. PMs induced increases in COX2 expression and PGE2 production, and decreased filaggrin expression. These effects were attenuated by pretreatment with COX2 inhibitor and PGE2 receptor antagonist, or after transfection with siRNAs of the aryl hydrocarbon receptor (AhR), gp91phox and p47phox. Furthermore, PM-induced generation of reactive oxygen species (ROS) and NADPH oxidase activity was attenuated by pretreatment with an AhR antagonist (AhRI) or antioxidants. Moreover, Nox-dependent ROS generation led to phosphorylation of ERK1/2, p38, and JNK, which then activated the downstream molecules NF-κB and AP-1, respectively. In vivo studies in PMs-treated mice showed that AhRI and apocynin (a Nox2 inhibitor) had anti-inflammatory effects by decreasing COX2 and increasing filaggrin expression. Our results reveal for the first time that PMs-induced ROS generation is mediated through the AhR/p47 phox/NADPH oxidase pathway, which in turn activates ERK1/2, p38/NF-κB and JNK/AP-1, and which ultimately induces COX2 expression and filaggrin downregulation. Up-regulated expression of COX2 and production of PGE2 may lead to impairment of skin barrier function.

  19. Cyclical DNA Methylation and Histone Changes Are Induced by LPS to Activate COX-2 in Human Intestinal Epithelial Cells

    PubMed Central

    Brancaccio, Mariarita; Coretti, Lorena; Florio, Ermanno; Pezone, Antonio; Calabrò, Viola; Falco, Geppino; Keller, Simona; Lembo, Francesca; Avvedimento, Vittorio Enrico; Chiariotti, Lorenzo

    2016-01-01

    Bacterial lipopolysaccharide (LPS) induces release of inflammatory mediators both in immune and epithelial cells. We investigated whether changes of epigenetic marks, including selected histone modification and DNA methylation, may drive or accompany the activation of COX-2 gene in HT-29 human intestinal epithelial cells upon exposure to LPS. Here we describe cyclical histone acetylation (H3), methylation (H3K4, H3K9, H3K27) and DNA methylation changes occurring at COX-2 gene promoter overtime after LPS stimulation. Histone K27 methylation changes are carried out by the H3 demethylase JMJD3 and are essential for COX-2 induction by LPS. The changes of the histone code are associated with cyclical methylation signatures at the promoter and gene body of COX-2 gene. PMID:27253528

  20. Antitumor Activity of Cytotoxic Cyclooxygenase-2 Inhibitors

    PubMed Central

    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

  1. Identification of potent, selective KDM5 inhibitors.

    PubMed

    Gehling, Victor S; Bellon, Steven F; Harmange, Jean-Christophe; LeBlanc, Yves; Poy, Florence; Odate, Shobu; Buker, Shane; Lan, Fei; Arora, Shilpi; Williamson, Kaylyn E; Sandy, Peter; Cummings, Richard T; Bailey, Christopher M; Bergeron, Louise; Mao, Weifeng; Gustafson, Amy; Liu, Yichin; VanderPorten, Erica; Audia, James E; Trojer, Patrick; Albrecht, Brian K

    2016-09-01

    This communication describes the identification and optimization of a series of pan-KDM5 inhibitors derived from compound 1, a hit initially identified against KDM4C. Compound 1 was optimized to afford compound 20, a 10nM inhibitor of KDM5A. Compound 20 is highly selective for the KDM5 enzymes versus other histone lysine demethylases and demonstrates activity in a cellular assay measuring the increase in global histone 3 lysine 4 tri-methylation (H3K4me3). In addition compound 20 has good ADME properties, excellent mouse PK, and is a suitable starting point for further optimization.

  2. Design, synthesis, and structure-activity relationship studies of fluorescent inhibitors of cycloxygenase-2 as targeted optical imaging agents.

    PubMed

    Uddin, Md Jashim; Crews, Brenda C; Ghebreselasie, Kebreab; Marnett, Lawrence J

    2013-04-17

    Cycloxygenase-2 (COX-2) is an attractive target for molecular imaging because it is an inducible enzyme that is expressed in response to inflammatory and proliferative stimuli. Recently, we reported that conjugation of indomethacin with carboxy-X-rhodamine dyes results in the formation of effective, targeted, optical imaging agents able to detect COX-2 in inflammatory tissues and premalignant and malignant tumors (Uddin et al. Cancer Res. 2010, 70, 3618-3627). The present paper summarizes the details of the structure-activity relationship (SAR) studies performed for lead optimization of these dyes. A wide range of fluorescent conjugates were designed and synthesized, and each of them was tested for the ability to selectively inhibit COX-2 as the purified protein and in human cancer cells. The SAR study revealed that indomethacin conjugates are the best COX-2-targeted agents compared to the other carboxylic acid-containing nonsteroidal anti-inflammatory drugs (NSAIDs) or COX-2-selective inhibitors (COXIBs). An n-butyldiamide linker is optimal for tethering bulky fluorescent functionalities onto the NSAID or COXIB cores. The activity of conjugates also depends on the size, shape, and electronic properties of the organic fluorophores. These reagents are taken up by COX-2-expressing cells in culture, and the uptake is blocked by pretreatment with a COX inhibitor. In in vivo settings, these reagents become highly enriched in COX-2-expressing tumors compared to surrounding normal tissue, and they accumulate selectively in COX-2-expressing tumors as compared with COX-2-negative tumors grown in mice. Thus, COX-2-targeted fluorescent inhibitors are useful for preclinical and clinical detection of lesions containing elevated levels of COX-2.

  3. Design, Synthesis, and Structure–Activity Relationship Studies of Fluorescent Inhibitors of Cycloxygenase-2 as Targeted Optical Imaging Agents

    PubMed Central

    2013-01-01

    Cycloxygenase-2 (COX-2) is an attractive target for molecular imaging because it is an inducible enzyme that is expressed in response to inflammatory and proliferative stimuli. Recently, we reported that conjugation of indomethacin with carboxy-X-rhodamine dyes results in the formation of effective, targeted, optical imaging agents able to detect COX-2 in inflammatory tissues and premalignant and malignant tumors (Uddin et al. Cancer Res. 2010, 70, 3618–3627). The present paper summarizes the details of the structure–activity relationship (SAR) studies performed for lead optimization of these dyes. A wide range of fluorescent conjugates were designed and synthesized, and each of them was tested for the ability to selectively inhibit COX-2 as the purified protein and in human cancer cells. The SAR study revealed that indomethacin conjugates are the best COX-2-targeted agents compared to the other carboxylic acid-containing nonsteroidal anti-inflammatory drugs (NSAIDs) or COX-2-selective inhibitors (COXIBs). An n-butyldiamide linker is optimal for tethering bulky fluorescent functionalities onto the NSAID or COXIB cores. The activity of conjugates also depends on the size, shape, and electronic properties of the organic fluorophores. These reagents are taken up by COX-2-expressing cells in culture, and the uptake is blocked by pretreatment with a COX inhibitor. In in vivo settings, these reagents become highly enriched in COX-2-expressing tumors compared to surrounding normal tissue, and they accumulate selectively in COX-2-expressing tumors as compared with COX-2-negative tumors grown in mice. Thus, COX-2-targeted fluorescent inhibitors are useful for preclinical and clinical detection of lesions containing elevated levels of COX-2. PMID:23488616

  4. Free radical scavenging and COX-2 inhibition by simple colon metabolites of polyphenols: A theoretical approach.

    PubMed

    Amić, Ana; Marković, Zoran; Marković, Jasmina M Dimitrić; Jeremić, Svetlana; Lučić, Bono; Amić, Dragan

    2016-12-01

    Free radical scavenging and inhibitory potency against cyclooxygenase-2 (COX-2) by two abundant colon metabolites of polyphenols, i.e., 3-hydroxyphenylacetic acid (3-HPAA) and 4-hydroxyphenylpropionic acid (4-HPPA) were theoretically studied. Different free radical scavenging mechanisms are investigated in water and pentyl ethanoate as a solvent. By considering electronic properties of scavenged free radicals, hydrogen atom transfer (HAT) and sequential proton loss electron transfer (SPLET) mechanisms are found to be thermodynamically probable and competitive processes in both media. The Gibbs free energy change for reaction of inactivation of free radicals indicates 3-HPAA and 4-HPPA as potent scavengers. Their reactivity toward free radicals was predicted to decrease as follows: hydroxyl>alkoxyls>phenoxyl≈peroxyls>superoxide. Shown free radical scavenging potency of 3-HPAA and 4-HPPA along with their high μM concentration produced by microbial colon degradation of polyphenols could enable at least in situ inactivation of free radicals. Docking analysis with structural forms of 3-HPAA and 4-HPPA indicates dianionic ligands as potent inhibitors of COX-2, an inducible enzyme involved in colon carcinogenesis. Obtained results suggest that suppressing levels of free radicals and COX-2 could be achieved by 3-HPAA and 4-HPPA indicating that these compounds may contribute to reduced risk of colon cancer development.

  5. Prolactin (PRL) induction of cyclooxygenase 2 (COX2) expression and prostaglandin (PG) production in hamster Leydig cells.

    PubMed

    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.

  6. Regulation of cytosolic COX-2 and prostaglandin E2 production by nitric oxide in activated murine macrophages.

    PubMed

    Patel, R; Attur, M G; Dave, M; Abramson, S B; Amin, A R

    1999-04-01

    Murine macrophages (RAW 264.7) when stimulated with LPS show 90% distribution of cyclooxygenase-2 (COX-2) in the nuclear fraction and approximately 10% in the cytosolic fraction. Further analysis of this cytosolic fraction at 100,000 x g indicates that the COX-2 is distributed both in the 100,000 x g soluble fraction and membrane fraction. Stimulation of RAW 264.7 cells with LPS in the presence of inducible nitric oxide synthase inhibitor L-NMMA at concentrations that inhibit nitrite accumulation by /=85% with higher concentrations of L-NMMA shows 1) up-regulation of PGE2 production, 2) accumulation of COX-2 protein in the 100,000 x g soluble and membrane fractions of the cytosolic fraction, and 3) with no significant effects on the accumulation of COX-2 mRNA. These experiments suggest that low concentrations of nitric oxide (10-15% of the total) attenuate PGE2 production in response to LPS in RAW 264.7 cells. This inhibition is, in part, due to decreased expression of cytosolic COX-2 protein.

  7. COX-2 gene expression is correlated with cognitive function in recurrent depressive disorder.

    PubMed

    Gałecki, Piotr; Talarowska, Monika; Bobińska, Kinga; Szemraj, Janusz

    2014-02-28

    Cyclooxygenase-2(COX-2) may be a key inflammatory enzyme involved in recurrent depressive disorder(rDD). In rDD group, COX-2 expression were higher and significant correlations occurred between COX-2 expression and cognitive functions. In controls there was no significant association between analysed variables. Thus, the COX-2 enzyme may be important for cognitive functioning in rDD.

  8. COX-2 is involved in vascular oxidative stress and endothelial dysfunction of renal interlobar arteries from obese Zucker rats.

    PubMed

    Muñoz, Mercedes; Sánchez, Ana; Pilar Martínez, María; Benedito, Sara; López-Oliva, Maria-Elvira; García-Sacristán, Albino; Hernández, Medardo; Prieto, Dolores

    2015-07-01

    Obesity is related to vascular dysfunction through inflammation and oxidative stress and it has been identified as a risk factor for chronic renal disease. In the present study, we assessed the specific relationships among reactive oxygen species (ROS), cyclooxygenase 2 (COX-2), and endothelial dysfunction in renal interlobar arteries from a genetic model of obesity/insulin resistance, the obese Zucker rats (OZR). Relaxations to acetylcholine (ACh) were significantly reduced in renal arteries from OZR compared to their counterpart, the lean Zucker rat (LZR), suggesting endothelial dysfunction. Blockade of COX with indomethacin and with the selective blocker of COX-2 restored the relaxations to ACh in obese rats. Selective blockade of the TXA2/PGH2 (TP) receptor enhanced ACh relaxations only in OZR, while inhibition of the prostacyclin (PGI2) receptor (IP) enhanced basal tone and inhibited ACh vasodilator responses only in LZR. Basal production of superoxide was increased in arteries of OZR and involved NADPH and xanthine oxidase activation and NOS uncoupling. Under conditions of NOS blockade, ACh induced vasoconstriction and increased ROS generation that were augmented in arteries from OZR and blunted by COX-2 inhibition and by the ROS scavenger tempol. Hydrogen peroxide (H2O2) evoked both endothelium- and vascular smooth muscle (VSM)-dependent contractions, as well as ROS generation that was reduced by COX-2 inhibition. In addition, COX-2 expression was enhanced in both VSM and endothelium of renal arteries from OZR. These results suggest that increased COX-2-dependent vasoconstriction contributes to renal endothelial dysfunction through enhanced (ROS) generation in obesity. COX-2 activity is in turn upregulated by ROS.

  9. Activation of COX-2/PGE2 Promotes Sapovirus Replication via the Inhibition of Nitric Oxide Production.

    PubMed

    Alfajaro, Mia Madel; Choi, Jong-Soon; Kim, Deok-Song; Seo, Ja-Young; Kim, Ji-Yun; Park, Jun-Gyu; Soliman, Mahmoud; Baek, Yeong-Bin; Cho, Eun-Hyo; Kwon, Joseph; Kwon, Hyung-Jun; Park, Su-Jin; Lee, Woo Song; Kang, Mun-Il; Hosmillo, Myra; Goodfellow, Ian; Cho, Kyoung-Oh

    2017-02-01

    Enteric caliciviruses in the genera Norovirus and Sapovirus are important pathogens that cause severe acute gastroenteritis in both humans and animals. Cyclooxygenases (COXs) and their final product, prostaglandin E2 (PGE2), are known to play important roles in the modulation of both the host response to infection and the replicative cycles of several viruses. However, the precise mechanism(s) by which the COX/PGE2 pathway regulates sapovirus replication remains largely unknown. In this study, infection with porcine sapovirus (PSaV) strain Cowden, the only cultivable virus within the genus Sapovirus, markedly increased COX-2 mRNA and protein levels at 24 and 36 h postinfection (hpi), with only a transient increase in COX-1 levels seen at 24 hpi. The treatment of cells with pharmacological inhibitors, such as nonsteroidal anti-inflammatory drugs or small interfering RNAs (siRNAs) against COX-1 and COX-2, significantly reduced PGE2 production, as well as PSaV replication. Expression of the viral proteins VPg and ProPol was associated with activation of the COX/PGE2 pathway. We observed that pharmacological inhibition of COX-2 dramatically increased NO production, causing a reduction in PSaV replication that could be restored by inhibition of nitric oxide synthase via the inhibitor N-nitro-l-methyl-arginine ester. This study identified a pivotal role for the COX/PGE2 pathway in the regulation of NO production during the sapovirus life cycle, providing new insights into the life cycle of this poorly characterized family of viruses. Our findings also reveal potential new targets for treatment of sapovirus infection.

  10. [Selective serotonin reuptake inhibitors (SSRI) and osteoporosis].

    PubMed

    Fétique-Will, Anne-Catherine; Chevalley, Thierry; Rizzoli, René

    2011-06-15

    Selective serotonin reuptake inhibitors (SSRI) represent the first-line treatment of depression. Several studies demonstrate that use of therapeutical doses of SSRI is associated with a decreased bone mineral density (BMD) and an increased risk of fracture. Mechanisms of action of SSRI on bone tissue are not totally clarified. These treatments would be associated with an increased risk of falls and would also have a direct effect on bone metabolism. Regarding proofs existing of the implication of SSRI on osteoporosis, while waiting for larger-scale prospective studies, it appears reasonable that practitioners assess bone loss within risk groups of patients treated with SSRI.

  11. [Selective serotonin reuptake inhibitor and gastrointestinal hemorrhage].

    PubMed

    Yamamoto, Takatsugu; Abe, Koichiro; Kuyama, Yasushi

    2013-04-01

    Selective serotonin reuptake inhibitors (SSRI) are widely used antidepressants characterized by less-frequent adverse effects compared with classical anti-depressive agents. On the other hand, SSRI can cause hemorrhagic events more due to impaired platelet aggregation induced by a depletion of serotonin in the peripheral platelet. Epidemiological studies have indicated that patients taking SSRI are predisposed to gastrointestinal hemorrhage, especially in case that nonsteroidal anti-inflammatory drugs are prescribed concomitantly. Here we describe a risk of the gastrointestinal hemorrhage in patients taking SSRI.

  12. Cell-type-specific roles for COX-2 in UVB-induced skin cancer.

    PubMed

    Jiao, Jing; Mikulec, Carol; Ishikawa, Tomo-o; Magyar, Clara; Dumlao, Darren S; Dennis, Edward A; Fischer, Susan M; Herschman, Harvey

    2014-06-01

    In human tumors, and in mouse models, cyclooxygenase-2 (COX-2) levels are frequently correlated with tumor development/burden. In addition to intrinsic tumor cell expression, COX-2 is often present in fibroblasts, myofibroblasts and endothelial cells of the tumor microenvironment, and in infiltrating immune cells. Intrinsic cancer cell COX-2 expression is postulated as only one of many sources for prostanoids required for tumor promotion/progression. Although both COX-2 inhibition and global Cox-2 gene deletion ameliorate ultraviolet B (UVB)-induced SKH-1 mouse skin tumorigenesis, neither manipulation can elucidate the cell type(s) in which COX-2 expression is required for tumorigenesis; both eliminate COX-2 activity in all cells. To address this question, we created Cox-2(flox/flox) mice, in which the Cox-2 gene can be eliminated in a cell-type-specific fashion by targeted Cre recombinase expression. Cox-2 deletion in skin epithelial cells of SKH-1 Cox-2(flox/flox);K14Cre(+) mice resulted, following UVB irradiation, in reduced skin hyperplasia and increased apoptosis. Targeted epithelial cell Cox-2 deletion also resulted in reduced tumor incidence, frequency, size and proliferation rate, altered tumor cell differentiation and reduced tumor vascularization. Moreover, Cox-2(flox/flox);K14Cre(+) papillomas did not progress to squamous cell carcinomas. In contrast, Cox-2 deletion in SKH-1 Cox-2(flox/flox); LysMCre(+) myeloid cells had no effect on UVB tumor induction. We conclude that (i) intrinsic epithelial COX-2 activity plays a major role in UVB-induced skin cancer, (ii) macrophage/myeloid COX-2 plays no role in UVB-induced skin cancer and (iii) either there may be another COX-2-dependent prostanoid source(s) that drives UVB skin tumor induction or there may exist a COX-2-independent pathway(s) to UVB-induced skin cancer.

  13. Cell-type-specific roles for COX-2 in UVB-induced skin cancer

    PubMed Central

    Herschman, Harvey

    2014-01-01

    In human tumors, and in mouse models, cyclooxygenase-2 (COX-2) levels are frequently correlated with tumor development/burden. In addition to intrinsic tumor cell expression, COX-2 is often present in fibroblasts, myofibroblasts and endothelial cells of the tumor microenvironment, and in infiltrating immune cells. Intrinsic cancer cell COX-2 expression is postulated as only one of many sources for prostanoids required for tumor promotion/progression. Although both COX-2 inhibition and global Cox-2 gene deletion ameliorate ultraviolet B (UVB)-induced SKH-1 mouse skin tumorigenesis, neither manipulation can elucidate the cell type(s) in which COX-2 expression is required for tumorigenesis; both eliminate COX-2 activity in all cells. To address this question, we created Cox-2 flox/flox mice, in which the Cox-2 gene can be eliminated in a cell-type-specific fashion by targeted Cre recombinase expression. Cox-2 deletion in skin epithelial cells of SKH-1 Cox-2 flox/flox;K14Cre + mice resulted, following UVB irradiation, in reduced skin hyperplasia and increased apoptosis. Targeted epithelial cell Cox-2 deletion also resulted in reduced tumor incidence, frequency, size and proliferation rate, altered tumor cell differentiation and reduced tumor vascularization. Moreover, Cox-2 flox/flox;K14Cre + papillomas did not progress to squamous cell carcinomas. In contrast, Cox-2 deletion in SKH-1 Cox-2 flox/flox; LysMCre + myeloid cells had no effect on UVB tumor induction. We conclude that (i) intrinsic epithelial COX-2 activity plays a major role in UVB-induced skin cancer, (ii) macrophage/myeloid COX-2 plays no role in UVB-induced skin cancer and (iii) either there may be another COX-2-dependent prostanoid source(s) that drives UVB skin tumor induction or there may exist a COX-2-independent pathway(s) to UVB-induced skin cancer. PMID:24469308

  14. Knipholone, a selective inhibitor of leukotriene metabolism.

    PubMed

    Wube, A A; Bucar, F; Asres, K; Gibbons, S; Adams, M; Streit, B; Bodensieck, A; Bauer, R

    2006-06-01

    Inhibition of leukotriene formation is one of the approaches to the treatment of asthma and other inflammatory diseases. We have investigated knipholone, isolated from the roots of Kniphofia foliosa, Hochst (Asphodelaceae), for inhibition of leukotriene biosynthesis in an ex vivo bioassay using activated human neutrophile granulocytes. Moreover, activities on 12-lipoxygenase from human platelets and cycloxygenase (COX)-1 and -2 from sheep cotyledons and seminal vesicles, respectively, have been evaluated. Knipholone was found to be a selective inhibitor of leukotriene metabolism in a human blood assay with an IC(50) value of 4.2microM. However, at a concentration of 10microg/ml, the compound showed weak inhibition of 12(S)-HETE production in human platelets and at a concentration of 50microM it produced no inhibition of COX-1 and -2. In our attempt to explain the mechanism of inhibition, we examined the antioxidant activity of knipholone using various in vitro assay systems including free radical scavenging, non-enzymatic lipid peroxidation, and metal chelation. Knipholone was found to be a weak dose-independent free radical scavenger and lipid peroxidation inhibitor, but not a metal chelator. Therefore, the leukotriene biosynthesis inhibitory effect of knipholone was evident by its ability either to inhibit the 5-lipoxygenase activating protein (FLAP) or as a competitive (non-redox) inhibitor of the enzyme. Cytotoxicity results also provided evidence that knipholone exhibits less toxicity for a mammalian host cell.

  15. Saturated fatty acids up-regulate COX-2 expression in prostate epithelial cells via toll-like receptor 4/NF-κB signaling.

    PubMed

    Liu, Jie; Hu, Shuai; Cui, Yun; Sun, Meng-Kui; Xie, Feng; Zhang, Qian; Jin, Jie

    2014-04-01

    Cyclooxygenase-2 (COX-2) has been implicated in prostate carcinogenesis, and recently it has been confirmed to be a molecular target of saturated fatty acids (SFAs). In the present study, we investigated the effect of stearic acid (SA) and palmitic acid (PA), two of the most abundant SFAs contained in dietary fat, on COX-2 expression in prostate epithelial cells and the signaling transduction pathway involved. First, we demonstrated that both SA and PA increased the mRNA and protein expression of COX-2, and consistently induced the activation of NF-κB in RWPE-1, BPH-1 and PC-3 prostate epithelial cell lines. The effect of SA and PA on COX-2 over-expression and NF-κB activation was in a dose-dependent manner, and PA was more potent than SA at the same concentration. Then, we demonstrated inhibition of NF-κB using its specific inhibitor strikingly attenuated PA-induced COX-2 expression. Toll-like receptor 4 (TLR4) was revealed to be expressed on RWPE-1, BPH-1 and PC-3 cell lines by PCR and immunofluorescence staining, and blocking its signaling significantly inhibited PA induced COX-2 over-expression and NF-κB activation. Taken together, we demonstrated that SFAs can up-regulate COX-2 expression in prostate epithelial cells, and this effect was mediated mainly through the TLR4/NF-κB signaling pathway.

  16. Thymoquinone suppresses migration of LoVo human colon cancer cells by reducing prostaglandin E2 induced COX-2 activation

    PubMed Central

    Hsu, Hsi-Hsien; Chen, Ming-Cheng; Day, Cecilia Hsuan; Lin, Yueh-Min; Li, Shin-Yi; Tu, Chuan-Chou; Padma, Viswanadha Vijaya; Shih, Hui-Nung; Kuo, Wei-Wen; Huang, Chih-Yang

    2017-01-01

    AIM To identify potential anti-cancer constituents in natural extracts that inhibit cancer cell growth and migration. METHODS Our experiments used high dose thymoquinone (TQ) as an inhibitor to arrest LoVo (a human colon adenocarcinoma cell line) cancer cell growth, which was detected by cell proliferation assay and immunoblotting assay. Low dose TQ did not significantly reduce LoVo cancer cell growth. Cyclooxygenase 2 (COX-2) is an enzyme that is involved in the conversion of arachidonic acid into prostaglandin E2 (PGE2) in humans. PGE2 can promote COX-2 protein expression and tumor cell proliferation and was used as a control. RESULTS Our results showed that 20 μmol/L TQ significantly reduced human LoVo colon cancer cell proliferation. TQ treatment reduced the levels of p-PI3K, p-Akt, p-GSK3β, and β-catenin and thereby inhibited the downstream COX-2 expression. Results also showed that the reduction in COX-2 expression resulted in a reduction in PGE2 levels and the suppression of EP2 and EP4 activation. Further analysis showed that TG treatment inhibited the nuclear translocation of β-catenin in LoVo cancer cells. The levels of the cofactors LEF-1 and TCF-4 were also decreased in the nucleus following TQ treatment in a dose-dependent manner. Treatment with low dose TQ inhibited the COX-2 expression at the transcriptional level and the regulation of COX-2 expression efficiently reduced LoVo cell migration. The results were further verified in vivo by confirming the effects of TQ and/or PGE2 using tumor xenografts in nude mice. CONCLUSION TQ inhibits LoVo cancer cell growth and migration, and this result highlights the therapeutic advantage of using TQ in combination therapy against colorectal cancer. PMID:28275297

  17. Renal effects of nabumetone, a COX-2 antagonist: impairment of function in isolated perfused rat kidneys contrasts with preserved renal function in vivo.

    PubMed

    Reichman, J; Cohen, S; Goldfarb, M; Shina, A; Rosen, S; Brezis, M; Karmeli, F; Heyman, S N

    2001-01-01

    The constitutive cyclooxygenase (COX)-1 enzyme has been considered the physiologically important isoform for prostaglandin synthesis in the normal kidney. It has, therefore, been suggested that selective inhibitors of the 'inducible' isoform (COX-2) may be free from renal adverse effects. We studied the renal effects of the predominantly COX-2 antagonist nabumetone in isolated perfused kidneys. As compared with controls, kidneys removed after in vivo administration of oral nabumetone (15 mg/kg) disclosed altered renal function with reduced glomerular filtration rate, filtration fraction, and urine volume and enhanced hypoxic outer medullary tubular damage. By contrast, renal function and morphology were not affected in vivo by nabumetone or its active metabolite 6-methoxy-2-naphthylacetic acid. The latter agent (10-20 mg/kg i.v.) did not significantly alter renal microcirculation, as opposed to a selective substantial reduction in medullary blood flow noted with the nonselective COX inhibitor indomethacin (5 mg/kg i.v.). In a rat model of acute renal failure, induced by concomitant administration of radiocontrast, nitric oxide synthase, and COX inhibitors, the decline in kidney function and the extent of hypoxic medullary damage with oral nabumetone (80 mg/kg) were comparable to a control group, and significantly less than those induced by indomethacin. In rats subjected to daily oral nabumetone for 3 consecutive weeks, renal function and morphology were preserved as well. Both nabumetone and 6-methoxy-2-naphthylacetic acid reduced renal parenchymal prostaglandin E2 to the same extent as indomethacin. It is concluded that while nabumetone adversely affects renal function and may intensify hypoxic medullary damage ex vivo, rat kidneys are not affected by this agent in vivo, both in acute and chronic studies. COX selectivity may not explain the renal safety of nabumetone.

  18. The effect of the intracervical administration of FSH or LH on the levels of hyaluronan, COX2, and COX2 mRNA in the cervix of the nonpregnant ewe.

    PubMed

    Leethongdee, Sukanya; Khalid, Muhammad; Scaramuzzi, Rex J

    2016-12-01

    During the periovulatory period, the cervix relaxes in response to changes in circulating concentrations of reproductive hormones. The present study investigated the role of gonadotrophins in cervical function by examining the expression of cyclooxygenase-2 (COX2) and COX2 mRNA and the concentration of hyaluronan (HA) in the cervix, after intracervical treatment with either FSH or LH. Eighteen ewes were assigned to four groups. They were then treated with commercial intravaginal progestagen sponges and eCG to synchronize their estrous cycles. Intracervical treatments were given 24 hours after removal of the sponges as follows: group 1: FSH, 2 mg; group 2: LH, 2 mg; group 3: vehicle; and group 4: control. Cervices were collected 54 hours after sponge removal and then divided into three regions. The expression of COX2 and COX2 mRNA was determined by immunohistochemistry and in situ hybridization and those of HA by ELISA. The levels of expression of COX2, COX2 mRNA, and HA were compared in six tissue layers (luminal epithelium, subepithelial stroma, circular, longitudinal and transverse muscle, and serosa) and in three cervical regions (vaginal, mid, and uterine). The results showed that both FSH and LH significantly increased the levels the COX2 mRNA and COX2 in the cervix, but the effects of the gonadotrophins were selective. The effects of both FSH and LH were most evident at the vaginal end of the cervix and least at the uterine end of the cervix. Furthermore, their effects were confined to the stroma and smooth muscle layers of the cervix in the case of FSH and to smooth muscle only in the case of LH. Neither FSH nor LH affected the concentration of HA in the cervix although FSH but not LH reduced the concentration of HA in cervical mucus. These findings suggest that the gonadotrophins regulate the expression of COX2 in the cervix and that they may have a role facilitating relaxation of the cervix during estrus in the ewe.

  19. MicroRNA-144 is regulated by CP2 and decreases COX-2 expression and PGE2 production in mouse ovarian granulosa cells.

    PubMed

    Zhou, Jiawei; Lei, Bin; Li, Huanan; Zhu, Lihua; Wang, Lei; Tao, Hu; Mei, Shuqi; Li, Fenge

    2017-02-09

    Mammalian folliculogenesis is a complex process in which primordial follicles develop into pre-ovulatory follicles, followed by ovulation to release mature oocytes. In this study, we explored the role of miR-144 in ovulation. miR-144 was one of the differentially expressed microRNAs, which showed 5.59-fold changes, in pre-ovulatory ovarian follicles between Large White and Chinese Taihu sows detected by Solexa deep sequencing. We demonstrated that overexpression of miR-144 significantly decreased the luciferase reporter activity under the control of the cyclooxygenase-2 (COX-2) or mothers against decapentaplegic homologue 4 (Smad4) 3'-untranslated region (3'-UTR) and suppressed COX-2 and Smad4 expression. In contrast, a miR-144 inhibitor increased COX-2 and Smad4 expression in mouse granulosa cells (mGCs). Meanwhile, Smad4 upregulated COX-2 expression, but this effect was abolished when the mGCs were treated with the transforming growth factor beta signalling pathway inhibitor SB431542. Moreover, luciferase reporter, chromatin immunoprecipitation and electrophoretic mobility shift assay results showed that the transcription factor CP2 upregulated miR-144 expression, which partially contributed to the suppression of COX-2 in mGCs. Both CP2 and miR-144 alter prostaglandin E2 (PGE2) production by regulating COX-2 expression. In addition, miR-144 regulated mGC apoptosis and affected follicular atresia, but these activities did not appear to be through COX-2 and Smad4. Taken together, we revealed an important CP2/miR-144/COX-2/PGE2/ovulation pathway in mGCs.

  20. Effects of β-glucosidase hydrolyzed products of harpagide and harpagoside on cyclooxygenase-2 (COX-2) in vitro.

    PubMed

    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.

  1. Chemical origins of isoform selectivity in histone deacetylase inhibitors.

    PubMed

    Butler, Kyle V; Kozikowski, Alan P

    2008-01-01

    Histones undergo extensive posttranslational modifications that affect gene expression. Acetylation is a key histone modification that is primarily regulated by two enzymes, one of which is histone deacetylase (HDAC). The activity of HDAC causes transcriptional silencing of DNA. Eleven distinct zinc-dependent histone deacetylase isoforms have been identified in humans. Each isoform has a unique structure and function, and regulates a unique set of genes. HDAC is responsible for the regulation of many genes involved in cancer cell proliferation, and it has been implicated in the pathogenesis of many neurological conditions. HDAC inhibitors are known to be very effective anti-cancer agents, and research has shown them to be potential treatments for many other conditions. Histone deacetylase inhibitors modify the expression of many genes, and it is possible that inhibition of one isoform could cause epigenetic changes that are beneficial to treatment of a disease, while inhibition of another isoform could cause contradictory changes. Selective HDAC inhibitors will be better able to avoid these types of situations than non-specific inhibitors, and may also be less toxic than pan-HDAC inhibitors. Many potent pan-HDAC inhibitors have already been developed, leaving the development of selective inhibitors at the forefront of HDAC drug development. Certain structural moieties may be added to HDAC inhibitors to give isoform selectivity, and these will be discussed in this review. This review will focus on the applications of selective HDAC inhibitors, inhibitors reported to show selectivity, and the relationship between inhibitor structure and selectivity.

  2. COX-2-dependent stabilization of survivin in non-small cell lung cancer.

    PubMed

    Krysan, Kostyantyn; Merchant, Farrukh H; Zhu, Li; Dohadwala, Mariam; Luo, Jie; Lin, Ying; Heuze-Vourc'h, Nathalie; Põld, Mehis; Seligson, David; Chia, David; Goodglick, Lee; Wang, Hejing; Strieter, Robert; Sharma, Sherven; Dubinett, Steven

    2004-01-01

    Elevated tumor cyclooxygenase 2 (COX-2) expression is associated with increased angiogenesis, tumor invasion and promotion of tumor cell resistance to apoptosis. The mechanism(s) by which COX-2 exerts its cytoprotective effects are not completely understood but may be due to an imbalance of pro- and anti-apoptotic gene expression. To analyze COX-2-dependent gene expression and apoptosis, we created cell lines constitutively expressing COX-2 cDNA in sense and antisense orientations. Whereas COX-2 sense cells have significantly heightened resistance to radiation and drug-induced apoptosis, COX-2 antisense cells are highly sensitive to apoptosis induction. We found that the expression of the anti-apoptotic protein survivin correlated positively with COX-2 expression. A COX-2-dependent modulation of survivin ubiquitination led to its stabilization in COX-2 overexpressing cells, and this effect was replicated by exogenous PGE2 treatment of parental tumor cells. In contrast to previous studies in other cell types, in nonsmall cell lung cancer cells survivin was expressed in a cell cycle-independent manner. When established in SCID mice in vivo, COX-2 antisense-derived tumors had significantly decreased survivin levels while COX-2 sense-derived tumors demonstrated elevated levels compared with controls. In accord with these findings, survivin and COX-2 were frequently upregulated and co-expressed in human lung cancers in situ.

  3. Virtual Dual inhibition of COX-2 / 5-LOX enzymes based on binding properties of alpha-amyrins, the anti-inflammatory compound as a promising anti-cancer drug.

    PubMed

    Ranjbar, Mohammad Mehdi; Assadolahi, Vahideh; Yazdani, Mohsen; Nikaein, Donya; Rashidieh, Behnam

    2016-01-01

    Hydro-alcoholic fruit extract of Cordia myxa was considerably effective on curing acute inflammation in mouse model. Previous studies suggested significant anti-inflammatory activities as well as potential anticancer agent of α-amyrins in seeds. Inhibition of Cyclooxygenase-2 (COX-2) and 5-Lipooxygenase (5-LOX) is significant in cancer prevention and therapeutics although this inhibition with chemo-drugs has its own side-effects. It is shown that these enzymes pathways are related to several cancers including colon, breast and lung cancer. This study was conducted based on Cordia species' α-amyrins as a safer natural anti-cancer compound for inhibition of COX-2 and 5-LOX enzymes by molecular docking. The X-ray crystal structure of COX2 / 5-LOX enzymes and α-amyrins was retrieved and energetically minimized respectively. The binding site and surface of enzymes were detected. Docking studies were performed by AutoDock 4.2 using Lamarckian genetic algorithm (LGA). Finally drug likeness, molecular pharmacokinetic properties and toxicity of α-amyrins was calculated. Molecular Docking revealed hydrogen and hydrophobic interactions between α-amyrins with both active sites of COX-2 and 5-LOX enzymes. Interestingly, it covalently bonded to Fe cofactor of 5-LOX enzyme and chelated this molecule. Base on binding energies (∆G) α-amyrin has more inhibitory effects on 5-LOX (-10.45 Kcal/mol) than COX-2 (-8.02 Kcal/mol). Analysis of molecular pharmacokinetic parameters suggested that α-amyrins complied with most sets of Lipinski's rules, and so it could be a suitable ligand for docking studies. Eventually, bioactivity score showed α-amyrins possess considerable biological activities as nuclear receptor, enzyme inhibitor, GPCR and protease inhibitor ligand. These results clearly demonstrate that α-amyrins could act as potential highly selective COX-/5-LOX inhibitor. Also, it is a safe compound in comparison with classical non-steroidal anti-inflammatory drugs (NSAIDs

  4. Virtual Dual inhibition of COX-2 / 5-LOX enzymes based on binding properties of alpha-amyrins, the anti-inflammatory compound as a promising anti-cancer drug

    PubMed Central

    Ranjbar, Mohammad Mehdi; Assadolahi, Vahideh; Yazdani, Mohsen; Nikaein, Donya; Rashidieh, Behnam

    2016-01-01

    Hydro-alcoholic fruit extract of Cordia myxa was considerably effective on curing acute inflammation in mouse model. Previous studies suggested significant anti-inflammatory activities as well as potential anticancer agent of α-amyrins in seeds. Inhibition of Cyclooxygenase-2 (COX-2) and 5-Lipooxygenase (5-LOX) is significant in cancer prevention and therapeutics although this inhibition with chemo-drugs has its own side-effects. It is shown that these enzymes pathways are related to several cancers including colon, breast and lung cancer. This study was conducted based on Cordia species' α-amyrins as a safer natural anti-cancer compound for inhibition of COX-2 and 5-LOX enzymes by molecular docking. The X-ray crystal structure of COX2 / 5-LOX enzymes and α-amyrins was retrieved and energetically minimized respectively. The binding site and surface of enzymes were detected. Docking studies were performed by AutoDock 4.2 using Lamarckian genetic algorithm (LGA). Finally drug likeness, molecular pharmacokinetic properties and toxicity of α-amyrins was calculated. Molecular Docking revealed hydrogen and hydrophobic interactions between α-amyrins with both active sites of COX-2 and 5-LOX enzymes. Interestingly, it covalently bonded to Fe cofactor of 5-LOX enzyme and chelated this molecule. Base on binding energies (∆G) α-amyrin has more inhibitory effects on 5-LOX (-10.45 Kcal/mol) than COX-2 (-8.02 Kcal/mol). Analysis of molecular pharmacokinetic parameters suggested that α-amyrins complied with most sets of Lipinski's rules, and so it could be a suitable ligand for docking studies. Eventually, bioactivity score showed α-amyrins possess considerable biological activities as nuclear receptor, enzyme inhibitor, GPCR and protease inhibitor ligand. These results clearly demonstrate that α-amyrins could act as potential highly selective COX-/5-LOX inhibitor. Also, it is a safe compound in comparison with classical non-steroidal anti-inflammatory drugs (NSAIDs

  5. Artesunate Induces Apoptosis of Bladder Cancer Cells by miR-16 Regulation of COX-2 Expression

    PubMed Central

    Zuo, Wei; Wang, Zhen-Zhong; Xue, Jun

    2014-01-01

    Bladder cancer is the most common malignant tumor of the urinary tract and remains one of the major causes of cancer death worldwide. In this study, we investigated the effect and mechanism of Artesunate (ART), a traditional Chinese medicine, on inducing apoptosis of human bladder cancer cells. In vivo antitumor activity was investigated in bladder cancer in rat by subcutaneous injection of different concentration of ART. The effect of ART on growth inhibition and apoptosis of bladder cancer cells was evaluated using dimethylthiazoly-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. Cyclooxygenase-2 (COX-2) and miR-16 expression levels were determined with real-time PCR. The concentrations of prostaglandin E2 (PGE2) in the supernatants of bladder cancer cells were measured with an ELISA kit. The miR-16 inhibitor or mimic were transfected into cells to up- or down-regulate miR-16 expression. ART efficiently inhibited orthotopic tumor growth in the bladder cancer rat, which is accompanied with an increase of miR-16 expression and a decrease of COX-2 expression. In vitro, ART could induce cytotoxicity and apoptosis in bladder cancer cells, but presented a much lighter toxicity effect against normal human urothelial cells. ART significantly increased miR-16 expression and decreased the expression of COX-2 and the production of PGE2. More importantly, down-regulation of miR-16 expression could reverse the effect of ART on apoptosis and COX-2 expression in bladder cells. Moreover, exogenous PGE2 could inhibit apoptosis of bladder cancer cells treated with ART. In conclusion, ART can elicit an anti-tumor effect against bladder cancer by up-regulation of miR-16 expression, which resulted in the decrease of COX-2 expression and PGE2 production. Hence, ART might be an effective drug for the treatment of bladder cancer. PMID:25196524

  6. Valdecoxib Recovers the Lipid Composition, Order and Dynamics in Colon Cancer Cell Lines Independent of COX-2 Expression: An ATR-FTIR Spectroscopy Study.

    PubMed

    Inan Genç, Aysun; Gok, Seher; Banerjee, Sreeparna; Severcan, Feride

    2017-01-01

    Prostanoids play an important role in a variety of physiological and pathophysiological processes including inflammation and cancer. The rate-limiting step in the prostanoid biosynthesis pathway is catalyzed by cyclooxygenases (COXs). Aberrant expression of the inducible isoform COX-2 plays a significant role in colon cancer initiation and progression. In this study, we have hypothesized that COX-2 specific inhibitors such as Valdecoxib (VLX), being highly hydrophobic, may alter biophysical properties of cellular lipids. In this study, COX-2 expressing (HT29) and COX-2 non-expressing (SW620) colon cancer cell lines were treated with VLX and examined using attenuated total reflection infrared spectroscopy. The results revealed that VLX treatment decreased lipid fluidity in the cells irrespective of COX-2 expression status and affected order parameters of the lipids in both cell lines. Cluster analysis also indicated that the spectral differences between the two cell lines are profound and could be successfully differentiated. Valdecoxib treatment could enhance the composition, order and dynamics of the lipids of colon cancer cells independently of its COX-2 inhibitory mechanism. Valdecoxib has therapeutic effects upon colon cancer, therefore it can be used as an adjuvant and/or chemopreventive agent for colon cancer.

  7. Rescue of Impaired Fracture Healing in COX-2−/− Mice via Activation of Prostaglandin E2 Receptor Subtype 4

    PubMed Central

    Xie, Chao; Liang, Bojian; Xue, Ming; Lin, Angela S.P.; Loiselle, Alayna; Schwarz, Edward M.; Guldberg, Robert E.; O'Keefe, Regis J.; Zhang, Xinping

    2009-01-01

    Although the essential role of cyclooxygenase (COX)-2 in fracture healing is known, the targeted genes and molecular pathways remain unclear. Using prostaglandin E2 receptor (EP)2 and EP4 agonists, we examined the effects of EP receptor activation in compensation for the lack of COX-2 during fracture healing. In a fracture-healing model, COX-2−/− mice showed delayed initiation and impaired endochondral bone repair, accompanied by a severe angiogenesis deficiency. The EP4 agonist markedly improved the impaired healing in COX-2−/− mice, as evidenced by restoration of bony callus formation on day 14, a near complete reversal of bone formation, and an approximately 70% improvement of angiogenesis in the COX-2−/− callus. In comparison, the EP2 agonist only marginally enhanced bone formation in COX-2−/− mice. To determine the differential roles of EP2 and EP4 receptors on COX-2-mediated fracture repair, the effects of selective EP agonists on chondrogenesis were examined in E11.5 long-term limb bud micromass cultures. Only the EP4 agonist significantly increased cartilage nodule formation similar to that observed during prostaglandin E2 treatment. The prostaglandin E2/EP4 agonist also stimulated MMP-9 expression in bone marrow stromal cell cultures. The EP4 agonist further restored the reduction of MMP-9 expression in the COX-2−/− fracture callus. Taken together, our studies demonstrate that EP2 and EP4 have differential functions during endochondral bone repair. Activation of EP4, but not EP2 rescued impaired bone fracture healing in COX-2−/− mice. PMID:19628768

  8. Transgenic expression of cyclooxygenase-2 (COX2) causes premature aging phenotypes in mice

    PubMed Central

    Feng, Mingxiao; Field, Kevin; Chatzistamou, Ioulia; Shim, Minsub

    2016-01-01

    Cyclooxygenase (COX) is a key enzyme in the biosynthesis of prostanoids, lipid signaling molecules that regulate various physiological processes. COX2, one of the isoforms of COX, is highly inducible in response to a wide variety of cellular and environmental stresses. Increased COX2 expression is thought to play a role in the pathogenesis of many age-related diseases. COX2 expression is also reported to be increased in the tissues of aged humans and mice, which suggests the involvement of COX2 in the aging process. However, it is not clear whether the increased COX2 expression is causal to or a result of aging. We have now addressed this question by creating an inducible COX2 transgenic mouse model. Here we show that post-natal expression of COX2 led to a panel of aging-related phenotypes. The expression of p16, p53, and phospho-H2AX was increased in the tissues of COX2 transgenic mice. Additionally, adult mouse lung fibroblasts from COX2 transgenic mice exhibited increased expression of the senescence-associated β-galactosidase. Our study reveals that the increased COX2 expression has an impact on the aging process and suggests that modulation of COX2 and its downstream signaling may be an approach for intervention of age-related disorders. PMID:27750221

  9. Activation of COX-2/PGE2 Promotes Sapovirus Replication via the Inhibition of Nitric Oxide Production

    PubMed Central

    Alfajaro, Mia Madel; Choi, Jong-Soon; Kim, Deok-Song; Seo, Ja-Young; Kim, Ji-Yun; Park, Jun-Gyu; Soliman, Mahmoud; Baek, Yeong-Bin; Cho, Eun-Hyo; Kwon, Joseph; Kwon, Hyung-Jun; Park, Su-Jin; Lee, Woo Song; Kang, Mun-Il; Hosmillo, Myra

    2016-01-01

    ABSTRACT Enteric caliciviruses in the genera Norovirus and Sapovirus are important pathogens that cause severe acute gastroenteritis in both humans and animals. Cyclooxygenases (COXs) and their final product, prostaglandin E2 (PGE2), are known to play important roles in the modulation of both the host response to infection and the replicative cycles of several viruses. However, the precise mechanism(s) by which the COX/PGE2 pathway regulates sapovirus replication remains largely unknown. In this study, infection with porcine sapovirus (PSaV) strain Cowden, the only cultivable virus within the genus Sapovirus, markedly increased COX-2 mRNA and protein levels at 24 and 36 h postinfection (hpi), with only a transient increase in COX-1 levels seen at 24 hpi. The treatment of cells with pharmacological inhibitors, such as nonsteroidal anti-inflammatory drugs or small interfering RNAs (siRNAs) against COX-1 and COX-2, significantly reduced PGE2 production, as well as PSaV replication. Expression of the viral proteins VPg and ProPol was associated with activation of the COX/PGE2 pathway. We observed that pharmacological inhibition of COX-2 dramatically increased NO production, causing a reduction in PSaV replication that could be restored by inhibition of nitric oxide synthase via the inhibitor N-nitro-l-methyl-arginine ester. This study identified a pivotal role for the COX/PGE2 pathway in the regulation of NO production during the sapovirus life cycle, providing new insights into the life cycle of this poorly characterized family of viruses. Our findings also reveal potential new targets for treatment of sapovirus infection. IMPORTANCE Sapoviruses are among the major etiological agents of acute gastroenteritis in both humans and animals, but little is known about sapovirus host factor requirements. Here, using only cultivable porcine sapovirus (PSaV) strain Cowden, we demonstrate that PSaV induced the vitalization of the cyclooxygenase (COX) and prostaglandin E2 (PGE2

  10. Crosstalk between osteoprotegerin (OPG), fatty acid synthase (FASN) and, cycloxygenase-2 (COX-2) in breast cancer: implications in carcinogenesis

    PubMed Central

    Goswami, Sudeshna; Sharma-Walia, Neelam

    2016-01-01

    The crosstalk between malignant and nonmalignant cells in the tumor microenvironment, as maneuvered by cytokines/chemokines, drives breast cancer progression. In our previous study, we discovered Osteoprotegerin (OPG) as one of the cytokines heavily secreted by breast cancer cells. We demonstrated that OPG is expressed and secreted at very high levels from the highly invasive breast cancer cell lines SUM149PT and SUM1315MO2 as compared to normal human mammary epithelial HMEC cells. OPG was involved in modulating aneuploidy, cell proliferation, and angiogenesis in breast cancer. Mass spectrometry analysis performed in this study revealed OPG interacts with fatty acid synthase (FASN), which is a key enzyme of the fatty acid biosynthetic pathway in breast cancer cells. Further, electron microscopy, immunofluorescence, and fluorescence quantitation assays highlighted the presence of a large number of lipid bodies (lipid droplets) in SUM149PT and SUM1315MO2 cells in comparison to HMEC. We recently showed upregulation of the COX-2 inflammatory pathway and its metabolite PGE2 secretion in SUM149PT and SUM1315MO2 breast cancer cells. Interestingly, human breast cancer tissue samples displayed high expression of OPG, PGE2 and fatty acid synthase (FASN). FASN is a multifunctional enzyme involved in lipid biosynthesis. Immunofluorescence staining revealed the co-existence of COX-2 and FASN in the lipid bodies of breast cancer cells. We reasoned that there might be crosstalk between OPG, FASN, and COX-2 that sustains the inflammatory pathways in breast cancer. Interestingly, knocking down OPG by CRISPR/Cas9 gene editing in breast cancer cells decreased FASN expression at the protein level. Here, we identified cis-acting elements involved in the transcriptional regulation of COX-2 and FASN by recombinant human OPG (rhOPG). Treatment with FASN inhibitor C75 and COX-2 inhibitor celecoxib individually decreased the number of lipid bodies/cell, downregulated phosphorylation of ERK

  11. The role of COX-2 in mediating the effect of PTEN on BMP9 induced osteogenic differentiation in mouse embryonic fibroblasts.

    PubMed

    Huang, Jun; Yuan, Shuang-Xue; Wang, Dong-Xu; Wu, Qiu-Xiang; Wang, Xing; Pi, Chang-Jun; Zou, Xiang; Chen, Liang; Ying, Liang-Jun; Wu, Ke; Yang, Jun-Qing; Sun, Wen-Juan; Deng, Zhong-Liang; He, Bai-Cheng

    2014-12-01

    Mouse embryonic fibroblasts (MEFs) are multi-potent progenitor cells (MPCs), can differentiate into different lineages, such as osteogenic, and adipogenic. PTEN, a tumor suppressor, may be involved in regulating bone development through interacting with COX-2. BMP9, the most potent osteogenic BMPs, can up-regulate COX-2 in MPCs. Whether PTEN is involved in BMP9 induced osteogenic differentiation in MPCs remains unknown. The goal of this investigation is to identify the effect of PTEN on BMP9-induced osteogenic differentiation in MPCs and dissect the possible mechanism underlay this. We found that BMP9 down-regulates PTEN, and PTEN inhibitor (VO) effectively increases different osteogenic markers induced by BMP9 in MEFs. Exogenous expression of PTEN inhibits BMP9 induced ectopic bone formation apparently. Mechanistically, we found that VO can enhance BMP9 induced BMPs/Smads signaling prominently without no substantial effects on cell cycle. Further analysis indicates that VO can promote BMP9-induced expression of COX-2 in MEFs, which can be eliminated by PI3K inhibitor. Additionally, COX-2 knockdown abolishes the effect of VO on BMP9-induced ALP activities in MEFs. Our findings suggest that PTEN plays an important role in regulating BMP9 induced osteogenic differentiation in MPCs, which may be mediated by PTEN/PI3K/Akt signaling to modulate the expression of COX-2.

  12. Regulation of Matrix Metalloproteinase-2 Activity by COX-2-PGE2-pAKT Axis Promotes Angiogenesis in Endometriosis

    PubMed Central

    Ray, Amlan K.; DasMahapatra, Pramathes; Swarnakar, Snehasikta

    2016-01-01

    Endometriosis is characterized by the ectopic development of the endometrium which relies on angiogenesis. Although studies have identified the involvement of different matrix metalloproteinases (MMPs) in endometriosis, no study has yet investigated the role of MMP-2 in endometriosis-associated angiogenesis. The present study aims to understand the regulation of MMP-2 activity in endothelial cells and on angiogenesis during progression of ovarian endometriosis. Histological and biochemical data showed increased expressions of vascular endothelial growth factor (VEGF), VEGF receptor-2, cycloxygenase (COX)-2, von Willebrand factor along with angiogenesis during endometriosis progression. Women with endometriosis showed decreased MMP-2 activity in eutopic endometrium as compared to women without endometriosis. However, ectopic ovarian endometrioma showed significantly elevated MMP-2 activity with disease severity. In addition, increased MT1MMP and decreased tissue inhibitors of metalloproteinases (TIMP)-2 expressions were found in the late stages of endometriosis indicating more MMP-2 activation with disease progression. In vitro study using human endothelial cells showed that prostaglandin E2 (PGE2) significantly increased MMP-2 activity as well as tube formation. Inhibition of COX-2 and/or phosphorylated AKT suppressed MMP-2 activity and endothelial tube formation suggesting involvement of PGE2 in regulation of MMP-2 activity during angiogenesis. Moreover, specific inhibition of MMP-2 by chemical inhibitor significantly reduced cellular migration, invasion and tube formation. In ovo assay showed decreased angiogenic branching upon MMP-2 inhibition. Furthermore, a significant reduction of lesion numbers was observed upon inhibition of MMP-2 and COX-2 in mouse model of endometriosis. In conclusion, our study establishes the involvement of MMP-2 activity via COX-2-PGE2-pAKT axis in promoting angiogenesis during endometriosis progression. PMID:27695098

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

    PubMed Central

    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

  14. Structure-based QSAR study on differential inhibition of human prostaglandin endoperoxide H synthase-2 (COX-2) by nonsteroidal anti-inflammatory drugs.

    PubMed

    Pouplana, R; Lozano, J J; Pérez, C; Ruiz, J

    2002-10-01

    The prostaglandin-endoperoxide H synthase-1 (PGHS- 1) and prostaglandin-endoperoxide H synthase-2 (PGHS-2) are the targets of nonsteroidal anti-inflammatory drugs (NSAIDs). It appears that the high degree of selectivity for inhibition of PGHS-2 shown by certain compounds is the result of two mechanisms (time-dependent, time-independent inhibition), by which they interact with each isoform. Molecular models of the complexes formed by indomethacin, sulindac, fenamates, 2-phenylpropionic acids and selective cyclooxygenase-2 (COX-2) inhibitors with the cyclooxygenase active site of human PGHS-2 have been built, paying particular attention to water molecules that participate in the hydrogen-bonding network at the polar active site entrance. The stability of the complexes has been assessed by molecular dynamics simulations and interaction energy decomposition analysis, and their biological significance has been discussed in light of available X-ray crystallographic and kinetic results. The selective PGHS-2 inhibitors exploit the extra space of a side-pocket in the active site of PGHS-2 that is not found in PGHS-1. The results suggest that active site hydration together with residues Tyr355, Glu524, Arg120 and Arg513 are crucial to understand the time-dependent inhibition mechanism. A marked relationship between the isoform selectivity and tightly interactions with residues into the side pocket bordered by Val523 is also found.

  15. Toward the understanding of the molecular basis for the inhibition of COX-1 and COX-2 by phenolic compounds present in Uruguayan propolis and grape pomace.

    PubMed

    Paulino, Margot; Alvareda, Elena; Iribarne, Federico; Miranda, Pablo; Espinosa, Victoria; Aguilera, Sara; Pardo, Helena

    2016-12-01

    Propolis and grape pomace have significant amounts of phenols which can take part in anti-inflammatory mechanisms. As the cyclooxygenases 1 and 2 (COX-1 and COX-2) are involved in said mechanisms, the possibility for a selective inhibition of COX-2 was analyzed in vitro and in silico. Propolis and grape pomace from Uruguayan species were collected, extracted in hydroalcoholic mixture and analyzed. Based on phenols previously identified, and taking as reference the crystallographic structures of COX-1 and COX-2 in complex with the commercial drug Celecoxib, a molecular docking procedure was devised to adjust 123 phenolic molecular models at the enzyme-binding sites. The most important results of this work are that the extracts have an overall inhibition activity very similar in COX-1 and COX-2, i.e. they do not possess selective inhibition activity for COX-2. Nevertheless, 10 compounds of the phenolic database turned out to be more selective and 94 phenols resulted with similar selectivity than Celecoxib, an outcome that accounts for the overall experimental inhibition measures. Binding site environment observations showed increased polarity in COX-2 as compared with COX-1, suggesting that polarity is the key for selectivity. Accordingly, the screening of molecular contacts pointed to the residues: Arg106, Gln178, Leu338, Ser339, Tyr341, Tyr371, Arg499, Ala502, Val509, and Ser516, which would explain, at the atomic level, the anti-inflammatory effect of the phenolic compounds. Among them, Gln178 and Arg499 appear to be essential for the selective inhibition of COX-2.

  16. iNOS signaling interacts with COX-2 pathway in colonic fibroblasts.

    PubMed

    Zhu, Yingting; Zhu, Min; Lance, Peter

    2012-10-01

    COX-2 and iNOS are two major inflammatory mediators implicated in colorectal inflammation and cancer. Previously, the role of colorectal fibroblasts involved in regulation of COX-2 and iNOS expression was largely ignored. In addition, the combined interaction of COX-2 and iNOS signalings and their significance in the progression of colorectal inflammation and cancer within the fibroblasts have received little investigation. To address those issues, we investigated the role of colonic fibroblasts in the regulation of COX-2 and iNOS gene expression, and explored possible mechanisms of interaction between COX-2 and iNOS signalings using a colonic CCD-18Co fibroblast line and LPS, a potential stimulator of COX-2 and iNOS. Our results clearly demonstrated that LPS activated COX-2 gene expression and enhanced PGE(2) production, stimulated iNOS gene expression and promoted NO production in the fibroblasts. Interestingly, activation of COX-2 signaling by LPS was not involved in activation of iNOS signaling, while activation of iNOS signaling by LPS contributed in part to activation of COX-2 signaling. Further analysis indicated that PKC plays a major role in the activation and interaction of COX-2 and iNOS signalings induced by LPS in the fibroblasts.

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

    PubMed

    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.

  18. Counteracting effect of TRPC1-associated Ca2+ influx on TNF-α-induced COX-2-dependent prostaglandin E2 production in human colonic myofibroblasts.

    PubMed

    Hai, Lin; Kawarabayashi, Yasuhiro; Imai, Yuko; Honda, Akira; Inoue, Ryuji

    2011-08-01

    TNF-α-NF-κB signaling plays a central role in inflammation, apoptosis, and neoplasia. One major consequence of this signaling in the gut is increased production of prostaglandin E(2) (PGE(2)) via cyclooxygenase-2 (COX-2) induction in myofibroblasts, which has been reported to be dependent on Ca(2+). In this study, we explored a potential role of canonical transient receptor potential (TRPC) proteins in this Ca(2+)-mediated signaling using a human colonic myofibroblast cell line CCD-18Co. In CCD-18Co cell, treatment with TNF-α greatly enhanced Ca(2+) influx induced by store depletion along with increased cell-surface expression of TRPC1 protein (but not of the other TRPC isoforms) and induction of a Gd(3+)-sensitive nonselective cationic conductance. Selective inhibition of TRPC1 expression by small interfering RNA (siRNA) or functionally effective TRPC1 antibody targeting the near-pore region of TRPC1 (T1E3) antagonized the enhancement of store-dependent Ca(2+) influx by TNF-α, whereas potentiated TNF-α induced PGE(2) production. Overexpression of TRPC1 in CCD-18Co produced opposite consequences. Inhibitors of NF-κB (curcumin, SN-50) attenuated TNF-α-induced enhancement of TRPC1 expression, store-dependent Ca(2+) influx, and COX-2-dependent PGE(2) production. In contrast, inhibition of calcineurin-nuclear factor of activated T-cell proteins (NFAT) signaling by FK506 or NFAT Activation Inhibitor III enhanced the PGE(2) production without affecting TRPC1 expression and the Ca(2+) influx. Finally, the suppression of store-dependent Ca(2+) influx by T1E3 antibody or siRNA knockdown significantly facilitated TNF-α-induced NF-κB nuclear translocation. In aggregate, these results strongly suggest that, in colonic myofibroblasts, NF-κB and NFAT serve as important positive and negative transcriptional regulators of TNF-α-induced COX-2-dependent PGE(2) production, respectively, at the downstream of TRPC1-associated Ca(2+) influx.

  19. A potent and selective inhibitor targeting human and murine 12/15-LOX.

    PubMed

    Armstrong, Michelle M; Freedman, Cody J; Jung, Joo Eun; Zheng, Yi; Kalyanaraman, Chakrapani; Jacobson, Matthew P; Simeonov, Anton; Maloney, David J; van Leyen, Klaus; Jadhav, Ajit; Holman, Theodore R

    2016-03-15

    Human reticulocyte 12/15-lipoxygenase (h12/15-LOX) is a lipid-oxidizing enzyme that can directly oxidize lipid membranes in the absence of a phospholipase, leading to a direct attack on organelles, such as the mitochondria. This cytotoxic activity of h12/15-LOX is up-regulated in neurons and endothelial cells after a stroke and thought to contribute to both neuronal cell death and blood-brain barrier leakage. The discovery of inhibitors that selectively target recombinant h12/15-LOX in vitro, as well as possessing activity against the murine ortholog ex vivo, could potentially support a novel therapeutic strategy for the treatment of stroke. Herein, we report a new family of inhibitors discovered in a High Throughput Screen (HTS) that are selective and potent against recombinant h12/15-LOX and cellular mouse 12/15-LOX (m12/15-LOX). MLS000099089 (compound 99089), the parent molecule, exhibits an IC50 potency of 3.4±0.5 μM against h12/15-LOX in vitro and an ex vivo IC50 potency of approximately 10 μM in a mouse neuronal cell line, HT-22. Compound 99089 displays greater than 30-fold selectivity versus h5-LOX and COX-2, 15-fold versus h15-LOX-2 and 10-fold versus h12-LOX, when tested at 20 μM inhibitor concentration. Steady-state inhibition kinetics reveals that the mode of inhibition of 99089 against h12/15-LOX is that of a mixed inhibitor with a Kic of 1.0±0.08 μM and a Kiu of 6.0±3.3 μM. These data indicate that 99089 and related derivatives may serve as a starting point for the development of anti-stroke therapeutics due to their ability to selectively target h12/15-LOX in vitro and m12/15-LOX ex vivo.

  20. Design of Fluorine-Containing 3,4-Diarylfuran-2(5H)-ones as Selective COX-1 Inhibitors.

    PubMed

    Uddin, Md Jashim; Elleman, Anna V; Ghebreselasie, Kebreab; Daniel, Cristina K; Crews, Brenda C; Nance, Kellie D; Huda, Tamanna; Marnett, Lawrence J

    2014-11-13

    We report the design and synthesis of fluorine-containing cyclooxygenase-1 (COX-1)-selective inhibitors to serve as prototypes for the development of a COX-1-targeted imaging agent. Deletion of the SO2CH3 group of rofecoxib switches the compound from a COX-2- to a COX-1-selective inhibitor, providing a 3,4-diarylfuran-2(5H)-one scaffold for structure-activity relationship studies of COX-1 inhibition. A wide range of fluorine-containing 3,4-diarylfuran-2(5H)-ones were designed, synthesized, and tested for their ability to selectively inhibit COX-1 in purified protein and human cancer cell assays. Compounds containing a fluoro-substituent on the C-3 phenyl ring and a methoxy-substituent on the C-4 phenyl ring of the 3,4-diarylfuran-2(5H)-one scaffold were the best COX-1-selective agents of those evaluated, exhibiting IC50s in the submicromolar range. These compounds provide the foundation for development of an agent to facilitate radiologic imaging of ovarian cancer expressing elevated levels of COX-1.

  1. Estrogenic/antiestrogenic activity of selected selective serotonin reuptake inhibitors

    PubMed Central

    POP, ANCA; LUPU, DIANA IOANA; CHERFAN, JULIEN; KISS, BELA; LOGHIN, FELICIA

    2015-01-01

    Background and aims Selective serotonin reuptake inhibitors (SSRIs) are one of the most prescribed classes of psychotropics. Even though the SSRI class consists of 6 molecules (citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine and sertraline), only fluoxetine was intensively studied for endocrine disruptive effects, while the other SSRIs received less attention. This study was designed to evaluate the estrogenic/antiestrogenic effect of fluoxetine, sertraline and paroxetine. Methods The in vitro (anti)estrogenic activity was assessed using a firefly luciferase reporter construct in the T47D-KBluc breast cancer cell line. These cells express nuclear estrogen receptors that can activate the transcription of the luciferase reporter gene upon binding of estrogen receptor agonists. Results All three compounds were found to interact with the estrogen receptor. Fluoxetine had dual properties, weak estrogenic at lower concentrations and antiestrogenic effect at higher concentrations. Sertraline shared the same properties with fluoxetine, but also increased the estradiol-mediated transcriptional activity. Paroxetine presented only one type of effect, the ability to increase the estradiol-mediated transcriptional activity. Conclusions Overall, our results indicate a possible interaction of SSRIs with the estrogen receptor. As SSRIs are being used by all categories of population, including pregnant women or children, establishing whether they can affect the endocrine mediated mechanisms should be a priority. PMID:26609273

  2. Genetic variants in COX-2, non-steroidal anti-inflammatory drugs, and breast cancer risk: the Western New York Exposures and Breast Cancer (WEB) Study.

    PubMed

    Brasky, Theodore M; Bonner, Matthew R; Moysich, Kirsten B; Ochs-Balcom, Heather M; Marian, Catalin; Ambrosone, Christine B; Nie, Jing; Tao, Meng Hua; Edge, Stephen B; Trevisan, Maurizio; Shields, Peter G; Freudenheim, Jo L

    2011-02-01

    Chronic inflammation has been consistently associated with cancers of several sites, including the breast, and inhibition of inflammation through the use of non-steroidal anti-inflammatory drugs (NSAIDs) has been inversely associated with risk. As NSAIDs bind with cyclooxygenase-2 (COX-2), genetic variation in COX-2 may influence breast cancer risk by affecting inflammatory response and response to NSAID use. We identified eight single nucleotide polymorphisms (SNPs) for COX-2 and examined their association with risk of breast cancer in a population-based case-control study in Western New York. Cases had incident, first primary, histologically confirmed breast cancer (n = 1077). Controls (n = 1910) were randomly selected from NY Department of Motor Vehicles records (< 65) or Medicare rolls (≥ 65). Participants were queried on adult lifetime use of aspirin and recent use of ibuprofen. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). One SNP, rs2745559, was associated with an increased risk of breast cancer (OR 1.23, 95% CI 1.03-1.46). Associations with other variants were not evident. Significant interaction (P interaction = 0.04) between recent aspirin use and rs4648261 was also observed. Variation in COX-2 was modestly associated with breast cancer risk, indicating that COX-2 may play a role in breast carcinogenesis. Better understanding of the role of COX-2 genetic variation and interaction with NSAID use in breast carcinogenesis has potential to inform prevention strategies.

  3. COX-2 over-expression correlates with VEGF and tumour angiogenesis in canine mammary cancer.

    PubMed

    Queiroga, Felisbina L; Pires, Isabel; Parente, Margarida; Gregório, Hugo; Lopes, Carlos S

    2011-07-01

    This study was designed to investigate the possible roles of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in canine mammary cancer angiogenesis. Immunohistochemistry was performed on 70 tumours (28 benign and 42 malignant) in order to detect COX-2 and VEGF expression. Microvessel density (MVD) was determined by CD31 immunolabelling to assess tumour angiogenesis. There was a significantly higher expression of COX-2 (P<0.001), VEGF (P<0.001) and MVD (P<0.001) in malignant compared to benign tumours. In the malignant group, the MVD of COX-2 positive tumours was significantly higher than that of COX-2 negative tumours (P=0.026). A similar association was observed for VEGF (P<0.001) positive tumours. The results from this study suggested that over-expression of COX-2 and VEGF may contribute to increased angiogenesis and aggression in malignant tumours.

  4. Cannabidiolic acid as a selective cyclooxygenase-2 inhibitory component in cannabis.

    PubMed

    Takeda, Shuso; Misawa, Koichiro; Yamamoto, Ikuo; Watanabe, Kazuhito

    2008-09-01

    In the present study it was revealed that cannabidiolic acid (CBDA) selectively inhibited cyclooxygenase (COX)-2 activity with an IC(50) value (50% inhibition concentration) around 2 microM, having 9-fold higher selectivity than COX-1 inhibition. In contrast, Delta(9)-tetrahydrocannabinolic acid (Delta(9)-THCA) was a much less potent inhibitor of COX-2 (IC(50) > 100 microM). Nonsteroidal anti-inflammatory drugs containing a carboxyl group in their chemical structures such as salicylic acid are known to inhibit nonselectively both COX-1 and COX-2. CBDA and Delta(9)-THCA have a salicylic acid moiety in their structures. Thus, the structural requirements for the CBDA-mediated COX-2 inhibition were next studied. There is a structural difference between CBDA and Delta(9)-THCA; phenolic hydroxyl groups of CBDA are freed from the ring formation with the terpene moiety, although Delta(9)-THCA has dibenzopyran ring structure. It was assumed that the whole structure of CBDA is important for COX-2 selective inhibition because beta-resorcylic acid itself did not inhibit COX-2 activity. Methylation of the carboxylic acid moiety of CBDA led to disappearance of COX-2 selectivity. Thus, it was suggested that the carboxylic acid moiety in CBDA is a key determinant for the inhibition. Furthermore, the crude extract of cannabis containing mainly CBDA was shown to have a selective inhibitory effect on COX-2. Taken together, these lines of evidence in this study suggest that naturally occurring CBDA in cannabis is a selective inhibitor for COX-2.

  5. JNK activation is essential for activation of MEK/ERK signaling in IL-1β-induced COX-2 expression in synovial fibroblasts

    PubMed Central

    Kitanaka, Taku; Nakano, Rei; Kitanaka, Nanako; Kimura, Taro; Okabayashi, Ken; Narita, Takanori; Sugiya, Hiroshi

    2017-01-01

    The proinflammatory cytokine interleukin 1β (IL-1β) induces prostaglandin E2 (PGE2) production via upregulation of cyclooxygenase-2 (COX-2) expression in synovial fibroblasts. This effect of IL-1β is involved in osteoarthritis. We investigated MAPK signaling pathways in IL-1β-induced COX-2 expression in feline synovial fibroblasts. In the presence of MAPK inhibitors, IL-1β-induced COX-2 expression and PGE2 release were both attenuated. IL-1β induced the phosphorylation of p38, JNK, MEK, and ERK1/2. A JNK inhibitor prevented not only JNK phosphorylation but also MEK and ERK1/2 phosphorylation in IL-1β-stimulated cells, but MEK and ERK1/2 inhibitors had no effect on JNK phosphorylation. A p38 inhibitor prevented p38 phosphorylation, but had no effect on MEK, ERK1/2, and JNK phosphorylation. MEK, ERK1/2, and JNK inhibitors had no effect on p38 phosphorylation. We also observed that in IL-1β-treated cells, phosphorylated MEK, ERK1/2, and JNK were co-precipitated with anti-phospho-MEK, ERK1/2, and JNK antibodies. The silencing of JNK1 in siRNA-transfected fibroblasts prevented IL-1β to induce phosphorylation of MEK and ERK1/2 and COX-2 mRNA expression. These observations suggest that JNK1 phosphorylation is necessary for the activation of the MEK/ERK1/2 pathway and the subsequent COX-2 expression for PGE2 release, and p38 independently contributes to the IL-1β effect in synovial fibroblasts. PMID:28054591

  6. Selective inhibition of inducible cyclooxygenase 2 in vivo is antiinflammatory and nonulcerogenic.

    PubMed Central

    Masferrer, J L; Zweifel, B S; Manning, P T; Hauser, S D; Leahy, K M; Smith, W G; Isakson, P C; Seibert, K

    1994-01-01

    We have examined the role of cyclooxygenase 2 (COX-2) in a model of inflammation in vivo. Carrageenan administration to the subcutaneous rat air pouch induces a rapid inflammatory response characterized by high levels of prostaglandins (PGs) and leukotrienes in the fluid exudate. The time course of the induction of COX-2 mRNA and protein coincided with the production of PGs in the pouch tissue and cellular infiltrate. Carrageenan-induced COX-2 immunoreactivity was localized to macrophages obtained from the fluid exudate as well as to the inner surface layer of cells within the pouch lining. Dexamethasone inhibited both COX-2 expression and PG synthesis in the fluid exudate but failed to inhibit PG synthesis in the stomach. Furthermore, NS-398, a selective COX-2 inhibitor, and indomethacin, a nonselective COX-1/COX-2 inhibitor, blocked proinflammatory PG synthesis in the air pouch. In contrast, only indomethacin blocked gastric PG and, additionally, produced gastric lesions. These results suggest that inhibitors of COX-2 are potent antiinflammatory agents which do not produce the typical side effects (e.g., gastric ulcers) associated with the nonselective, COX-1-directed antiinflammatory drugs. Images PMID:8159730

  7. Lineage-specific fragmentation and nuclear relocation of the mitochondrial cox2 gene in chlorophycean green algae (Chlorophyta).

    PubMed

    Rodríguez-Salinas, Elizabeth; Riveros-Rosas, Héctor; Li, Zhongkui; Fucíková, Karolina; Brand, Jerry J; Lewis, Louise A; González-Halphen, Diego

    2012-07-01

    In most eukaryotes the subunit 2 of cytochrome c oxidase (COX2) is encoded in intact mitochondrial genes. Some green algae, however, exhibit split cox2 genes (cox2a and cox2b) encoding two polypeptides (COX2A and COX2B) that form a heterodimeric COX2 subunit. Here, we analyzed the distribution of intact and split cox2 gene sequences in 39 phylogenetically diverse green algae in phylum Chlorophyta obtained from databases (28 sequences from 22 taxa) and from new cox2 data generated in this work (23 sequences from 18 taxa). Our results support previous observations based on a smaller number of taxa, indicating that algae in classes Prasinophyceae, Ulvophyceae, and Trebouxiophyceae contain orthodox, intact mitochondrial cox2 genes. In contrast, all of the algae in Chlorophyceae that we examined exhibited split cox2 genes, and could be separated into two groups: one that has a mitochondrion-localized cox2a gene and a nucleus-localized cox2b gene ("Scenedesmus-like"), and another that has both cox2a and cox2b genes in the nucleus ("Chlamydomonas-like"). The location of the split cox2a and cox2b genes was inferred using five different criteria: differences in amino acid sequences, codon usage (mitochondrial vs. nuclear), codon preference (third position frequencies), presence of nucleotide sequences encoding mitochondrial targeting sequences and presence of spliceosomal introns. Distinct green algae could be grouped according to the form of cox2 gene they contain: intact or fragmented, mitochondrion- or nucleus-localized, and intron-containing or intron-less. We present a model describing the events that led to mitochondrial cox2 gene fragmentation and the independent and sequential migration of cox2a and cox2b genes to the nucleus in chlorophycean green algae. We also suggest that the distribution of the different forms of the cox2 gene provides important insights into the phylogenetic relationships among major groups of Chlorophyceae.

  8. Significance of Cox-2 expression in rectal cancers with or without preoperative radiotherapy

    SciTech Connect

    Pachkoria, Ketevan; Zhang Hong; Adell, Gunnar; Jarlsfelt, Ingvar; Sun Xiaofeng . E-mail: xiao-feng.sun@ibk.liu.se

    2005-11-01

    Purpose: Radiotherapy has reduced local recurrence of rectal cancers, but the result is not satisfactory. Further biologic factors are needed to identify patients for more effective radiotherapy. Our aims were to investigate the relationship of cyclooxygenase-2 (Cox-2) expression to radiotherapy, and clinicopathologic/biologic variables in rectal cancers with or without radiotherapy. Methods and Materials: Cox-2 expression was immunohistochemically examined in distal normal mucosa (n = 28), in adjacent normal mucosa (n = 107), in primary cancer (n = 138), lymph node metastasis (n = 30), and biopsy (n = 85). The patients participated in a rectal cancer trial of preoperative radiotherapy. Results: Cox-2 expression was increased in primary tumor compared with normal mucosa (p < 0.0001), but there was no significant change between primary tumor and metastasis. Cox-2 positivity was or tended to be related to more p53 and Ki-67 expression, and less apoptosis (p {<=} 0.05). In Cox-2-negative cases of either biopsy (p = 0.01) or surgical samples (p = 0.02), radiotherapy was related to less frequency of local recurrence, but this was not the case in Cox-2-positive cases. Conclusion: Cox-2 expression seemed to be an early event involved in rectal cancer development. Radiotherapy might reduce a rate of local recurrence in the patients with Cox-2 weakly stained tumors, but not in those with Cox-2 strongly stained tumors.

  9. Alteration of femoral bone morphology and density in COX-2-/- mice.

    PubMed

    Robertson, Galen; Xie, Chao; Chen, Di; Awad, Hani; Schwarz, Edward M; O'Keefe, Regis J; Guldberg, Robert E; Zhang, Xinping

    2006-10-01

    A role of COX-2 in pathological bone destruction and fracture repair has been established; however, few studies have been conducted to examine the involvement of COX-2 in maintaining bone mineral density and bone micro-architecture. In this study, we examined bone morphology in multiple trabecular and cortical regions within the distal and diaphyseal femur of 4-month-old wild-type and COX-2-/- mice using micro-computed tomography. Our results demonstrated that while COX-2-/- female mice had normal bone geometry and trabecular microarchitecture at 4 months of age, the male knockout mice displayed reduced bone volume fraction within the distal femoral metaphysis. Furthermore, male COX-2-/- mice had a significant reduction in cortical bone mineral density within the central cortical diaphysis and distal epiphysis and metaphysis. Consistent with the observed reduction in cortical mineral density, biomechanical testing via 4-point-bending showed that male COX-2-/- mice had a significant increase in postyield deformation, indicating a ductile bone phenotype in male COX-2-/- mice. In conclusion, our study suggests that genetic ablation of COX-2 may have a sex-related effect on cortical bone homeostasis and COX-2 plays a role in maintaining normal bone micro-architecture and density in mice.

  10. Alteration of femoral bone morphology and density in COX-2−/− mice

    PubMed Central

    Robertson, Galen; Xie, Chao; Chen, Di; Awad, Hani; Schwarz, Edward M.; O’Keefe, Regis J.; Guldberg, Robert E.; Zhang, Xinping

    2009-01-01

    A role of COX-2 in pathological bone destruction and fracture repair has been established; however, few studies have been conducted to examine the involvement of COX-2 in maintaining bone mineral density and bone micro-architecture. In this study, we examined bone morphology in multiple trabecular and cortical regions within the distal and diaphyseal femur of 4-month-old wild-type and COX-2−/− mice using micro-computed tomography. Our results demonstrated that while COX-2−/− female mice had normal bone geometry and trabecular microarchitecture at 4 months of age, the male knockout mice displayed reduced bone volume fraction within the distal femoral metaphysis. Furthermore, male COX-2−/− mice had a significant reduction in cortical bone mineral density within the central cortical diaphysis and distal epiphysis and metaphysis. Consistent with the observed reduction in cortical mineral density, biomechanical testing via 4-point-bending showed that male COX-2−/− mice had a significant increase in postyield deformation, indicating a ductile bone phenotype in male COX-2−/− mice. In conclusion, our study suggests that genetic ablation of COX-2 may have a sex-related effect on cortical bone homeostasis and COX-2 plays a role in maintaining normal bone micro-architecture and density in mice. PMID:16731065

  11. The antioxidant effects of isorhamnetin contribute to inhibit COX-2 expression in response to inflammation: a potential role of HO-1.

    PubMed

    Seo, Kyuhwa; Yang, Ji Hye; Kim, Sang Chan; Ku, Sae Kwang; Ki, Sung Hwan; Shin, Sang Mi

    2014-06-01

    Previously, we reported that isorhamnentin, a 3'-O-methylated metabolite of quercetin, reduced inducible nitric oxide synthase (iNOS) expression and NO production. The present study further investigated the underlying mechanism of anti-inflammatory and antioxidant effects of isorhamnentin. Administration of isorhamnetin decreased the number of cyclooxygenase-2 (COX-2) positive cells in rats with carrageenan-induced paw edema. Isorhamnetin also suppressed lipopolysaccharide (LPS)-induced expression of COX-2 in cells. It is well known that LPS-induced reactive oxygen species (ROS) production leads to COX-2 induction. Isorhamnetin decreased LPS-induced ROS production and apoptosis. In addition, the basal expression of heme oxygenase-1 (HO-1) was increased by isorhamnetin treatment in agreement with the increase in nuclear translocation of NF-E2-related factor-2 (Nrf2), an essential transcription factor for the regulation of HO-1 expression. Moreover, pretreatment of tin protoporphyrin IX (SnPP), a chemical inhibitor of HO-1, reversed the ability of isothamnetin to inhibit COX-2 expression. These results demonstrate that induction of HO-1 by isorhamnetin leads to a reduction in ROS production and its antioxidant property might contribute to the inhibition of COX-2 expression in response to inflammation.

  12. Allelic variation in the canine Cox-2 promoter causes hypermethylation of the canine Cox-2 promoter in clinical cases of renal dysplasia

    PubMed Central

    2014-01-01

    Background Novel allelic variants in the promoter of the canine cyclooxygenase-2 (Cox-2) gene are associated with renal dysplasia (RD). These variants consist of either deletions of putative SP1 transcription factor-binding sites or insertions of tandem repeats of SP1-binding sites located in the CpG island just upstream of the ATG translation initiation site. The canine Cox-2 gene was studied because Cox-2-deficient mice have renal abnormalities and a pathology that is strikingly similar to RD in dogs. Findings The allelic variants were associated with hypermethylation of the Cox-2 promoter only in clinical cases of RD. The wild-type allele was never methylated, even in clinical cases that were heterozygous for a mutant allele. In cases that were biopsy-negative, the promoter remained unmethylated, regardless of the genotype. Methylated DNA was found in DNA from various adult tissues of dogs with clinical RD. Conclusions The mechanism of action of the allelic variation in the canine Cox-2 promoter most likely involves variation in the extent of epigenetic downregulation of this gene. This epigenetic downregulation must have occurred early in development because methylated Cox-2 promoter DNA sequences are found in various adult tissues. PMID:24708682

  13. Selective serotonin reuptake inhibitors for fibromyalgia syndrome

    PubMed Central

    Walitt, Brian; Urrútia, Gerard; Nishishinya, María Betina; Cantrell, Sarah E; Häuser, Winfried

    2016-01-01

    Background Fibromyalgia is a clinically well-defined chronic condition with a biopsychosocial aetiology. Fibromyalgia is characterized by chronic widespread musculoskeletal pain, sleep problems, cognitive dysfunction, and fatigue. Patients often report high disability levels and poor quality of life. Since there is no specific treatment that alters the pathogenesis of fibromyalgia, drug therapy focuses on pain reduction and improvement of other aversive symptoms. Objectives The objective was to assess the benefits and harms of selective serotonin reuptake inhibitors (SSRIs) in the treatment of fibromyalgia. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 5), MEDLINE (1966 to June 2014), EMBASE (1946 to June 2014), and the reference lists of reviewed articles. Selection criteria We selected all randomized, double-blind trials of SSRIs used for the treatment of fibromyalgia symptoms in adult participants. We considered the following SSRIs in this review: citalopram, fluoxetine, escitalopram, fluvoxamine, paroxetine, and sertraline. Data collection and analysis Three authors extracted the data of all included studies and assessed the risks of bias of the studies. We resolved discrepancies by discussion. Main results The quality of evidence was very low for each outcome. We downgraded the quality of evidence to very low due to concerns about risk of bias and studies with few participants. We included seven placebo-controlled studies, two with citalopram, three with fluoxetine and two with paroxetine, with a median study duration of eight weeks (4 to 16 weeks) and 383 participants, who were pooled together. All studies had one or more sources of potential major bias. There was a small (10%) difference in patients who reported a 30% pain reduction between SSRIs (56/172 (32.6%)) and placebo (39/171 (22.8%)) risk difference (RD) 0.10, 95% confidence interval (CI) 0.01 to 0.20; number needed to treat for an additional

  14. Development of a potent and selective cell penetrant Legumain inhibitor.

    PubMed

    Ness, Kerry A; Eddie, Sharon L; Higgins, Catherine A; Templeman, Amy; D'Costa, Zenobia; Gaddale, Kishore K D; Bouzzaoui, Samira; Jordan, Linda; Janssen, Dominic; Harrison, Timothy; Burkamp, Frank; Young, Andrew; Burden, Roberta; Scott, Christopher J; Mullan, Paul B; Williams, Rich

    2015-12-01

    This Letter describes the continued SAR exploration of small molecule Legumain inhibitors with the aim of developing a potent and selective in vitro tool compound. Work continued in this Letter explores the use of alternative P2-P3 linker units and the P3 group SAR which led to the identification of 10t, a potent, selective and cellularly active Legumain inhibitor. We also demonstrate that 10t has activity in both cancer cell viability and colony formation assays.

  15. In Polytomella sp. mitochondria, biogenesis of the heterodimeric COX2 subunit of cytochrome c oxidase requires two different import pathways.

    PubMed

    Jiménez-Suárez, Alejandra; Vázquez-Acevedo, Miriam; Rojas-Hernández, Andrés; Funes, Soledad; Uribe-Carvajal, Salvador; González-Halphen, Diego

    2012-05-01

    In the vast majority of eukaryotic organisms, the mitochondrial cox2 gene encodes subunit II of cytochrome c oxidase (COX2). However, in some lineages including legumes and chlorophycean algae, the cox2 gene migrated to the nucleus. Furthermore, in chlorophycean algae, this gene was split in two different units. Thereby the COX2 subunit is encoded by two independent nuclear genes, cox2a and cox2b, and mitochondria have to import the cytosol-synthesized COX2A and COX2B subunits and assemble them into the cytochrome c oxidase complex. In the chlorophycean algae Chlamydomonas reinhardtii and Polytomella sp., the COX2A precursor exhibits a long (130-140 residues), cleavable mitochondrial targeting sequence (MTS). In contrast, COX2B lacks an MTS, suggesting that mitochondria use different mechanisms to import each subunit. Here, we explored the in vitro import processes of both, the Polytomella sp. COX2A precursor and the COX2B protein. We used isolated, import-competent mitochondria from this colorless alga. Our results suggest that COX2B is imported directly into the intermembrane space, while COX2A seems to follow an energy-dependent import pathway, through which it finally integrates into the inner mitochondrial membrane. In addition, the MTS of the COX2A precursor is eliminated. This is the first time that the in vitro import of split COX2 subunits into mitochondria has been achieved.

  16. Origin of the spin reorientation transitions in (Fe1–xCox)2B alloys

    DOE PAGES

    Belashchenko, Kirill D.; Ke, Liqin; Däne, Markus; ...

    2015-02-13

    Low-temperature measurements of the magnetocrystalline anisotropy energy K in (Fe1–xCox)2B alloys are reported, and the origin of this anisotropy is elucidated using a first-principles electronic structure analysis. The calculated concentration dependence K(x) with a maximum near x = 0.3 and a minimum near x = 0.8 is in excellent agreement with experiment. This dependence is traced down to spin-orbital selection rules and the filling of electronic bands with increasing electronic concentration. In conclusion, at the optimal Co concentration, K depends strongly on the tetragonality and doubles under a modest 3% increase of the c/a ratio, suggesting that the magnetocrystalline anisotropymore » can be further enhanced using epitaxial or chemical strain.« less

  17. Acalabrutinib (ACP-196): a selective second-generation BTK inhibitor.

    PubMed

    Wu, Jingjing; Zhang, Mingzhi; Liu, Delong

    2016-03-09

    More and more targeted agents become available for B cell malignancies with increasing precision and potency. The first-in-class Bruton's tyrosine kinase (BTK) inhibitor, ibrutinib, has been in clinical use for the treatment of chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstrom's macroglobulinemia. More selective BTK inhibitors (ACP-196, ONO/GS-4059, BGB-3111, CC-292) are being explored. Acalabrutinib (ACP-196) is a novel irreversible second-generation BTK inhibitor that was shown to be more potent and selective than ibrutinib. This review summarized the preclinical research and clinical data of acalabrutinib.

  18. Screening of selective histone deacetylase inhibitors by proteochemometric modeling

    PubMed Central

    2012-01-01

    Background Histone deacetylase (HDAC) is a novel target for the treatment of cancer and it can be classified into three classes, i.e., classes I, II, and IV. The inhibitors selectively targeting individual HDAC have been proved to be the better candidate antitumor drugs. To screen selective HDAC inhibitors, several proteochemometric (PCM) models based on different combinations of three kinds of protein descriptors, two kinds of ligand descriptors and multiplication cross-terms were constructed in our study. Results The results show that structure similarity descriptors are better than sequence similarity descriptors and geometry descriptors in the leftacterization of HDACs. Furthermore, the predictive ability was not improved by introducing the cross-terms in our models. Finally, a best PCM model based on protein structure similarity descriptors and 32-dimensional general descriptors was derived (R2 = 0.9897, Qtest2 = 0.7542), which shows a powerful ability to screen selective HDAC inhibitors. Conclusions Our best model not only predict the activities of inhibitors for each HDAC isoform, but also screen and distinguish class-selective inhibitors and even more isoform-selective inhibitors, thus it provides a potential way to discover or design novel candidate antitumor drugs with reduced side effect. PMID:22913517

  19. Endomicroscopic Imaging of COX-2 Activity in Murine Sporadic and Colitis-Associated Colorectal Cancer

    PubMed Central

    Foersch, Sebastian; Neufert, Clemens; Neurath, Markus F.; Waldner, Maximilian J.

    2013-01-01

    Although several studies propose a chemopreventive effect of aspirin for colorectal cancer (CRC) development, the general use of aspirin cannot be recommended due to its adverse side effects. As the protective effect of aspirin has been associated with an increased expression of COX-2, molecular imaging of COX-2, for instance, during confocal endomicroscopy could enable the identification of patients who would possibly benefit from aspirin treatment. In this pilot trial, we used a COX-2-specific fluorescent probe for detection of colitis-associated and sporadic CRC in mice using confocal microscopy. Following the injection of the COX-2 probe into tumor-bearing APCmin mice or mice exposed to the AOM + DSS model of colitis-associated cancer, the tumor-specific upregulation of COX-2 could be validated with in vivo fluorescence imaging. Subsequent confocal imaging of tumor tissue showed an increased number of COX-2 expressing cells when compared to the normal mucosa of healthy controls. COX-2-expression was detectable with subcellular resolution in tumor cells and infiltrating stroma cells. These findings pose a proof of concept and suggest the use of CLE for the detection of COX-2 expression during colorectal cancer surveillance endoscopy. This could improve early detection and stratification of chemoprevention in patients with CRC. PMID:23401648

  20. Endomicroscopic Imaging of COX-2 Activity in Murine Sporadic and Colitis-Associated Colorectal Cancer.

    PubMed

    Foersch, Sebastian; Neufert, Clemens; Neurath, Markus F; Waldner, Maximilian J

    2013-01-01

    Although several studies propose a chemopreventive effect of aspirin for colorectal cancer (CRC) development, the general use of aspirin cannot be recommended due to its adverse side effects. As the protective effect of aspirin has been associated with an increased expression of COX-2, molecular imaging of COX-2, for instance, during confocal endomicroscopy could enable the identification of patients who would possibly benefit from aspirin treatment. In this pilot trial, we used a COX-2-specific fluorescent probe for detection of colitis-associated and sporadic CRC in mice using confocal microscopy. Following the injection of the COX-2 probe into tumor-bearing APCmin mice or mice exposed to the AOM + DSS model of colitis-associated cancer, the tumor-specific upregulation of COX-2 could be validated with in vivo fluorescence imaging. Subsequent confocal imaging of tumor tissue showed an increased number of COX-2 expressing cells when compared to the normal mucosa of healthy controls. COX-2-expression was detectable with subcellular resolution in tumor cells and infiltrating stroma cells. These findings pose a proof of concept and suggest the use of CLE for the detection of COX-2 expression during colorectal cancer surveillance endoscopy. This could improve early detection and stratification of chemoprevention in patients with CRC.

  1. IL-20, an anti-angiogenic cytokine that inhibits COX-2 expression.

    PubMed

    Heuzé-Vourc'h, Nathalie; Liu, Ming; Dalwadi, Harnisha; Baratelli, Felicita E; Zhu, Li; Goodglick, Lee; Põld, Mehis; Sharma, Sherven; Ramirez, Ruben D; Shay, Jerry W; Minna, John D; Strieter, Robert M; Dubinett, Steven M

    2005-07-29

    COX-2 overexpression and subsequent PGE(2) production are frequently associated with non-small cell lung cancer and are implicated in tumor-mediated angiogenesis. Here, we report for the first time that IL-20 downregulates COX-2 and PGE(2) in human bronchial epithelial and endothelial cells. Flow cytometry analysis suggests that IL-20-dependent inhibition of COX-2/PGE(2) occurs through the IL-22R1/IL-20R2 dimers. In addition, we report that IL-20 exerts anti-angiogenic effects, inhibiting experimental angiogenesis. IL-20-mediated inhibition of PMA-induced angiogenesis occurs through the COX-2 regulatory pathway. Altogether our findings revealed that IL-20 is a negative modulator of COX-2/PGE(2) and inhibits angiogenesis.

  2. Identification of new peptide amides as selective cathepsin L inhibitors: the first step towards selective irreversible inhibitors?

    PubMed

    Torkar, Ana; Lenarčič, Brigita; Lah, Tamara; Dive, Vincent; Devel, Laurent

    2013-05-15

    A small library of peptide amides was designed to profile the cathepsin L active site. Within the cathepsin family of cysteine proteases, the first round of selection was on cathepsin L and cathepsin B, and then selected hits were further evaluated for binding to cathepsin K and cathepsin S. Five highly selective sequences with submicromolar affinities towards cathepsin L were identified. An acyloxymethyl ketone warhead was then attached to these sequences. Although these original irreversible inhibitors inactivate cathepsin L, it appears that the nature of the warhead drastically impact the selectivity profile of the resulting covalent inhibitors.

  3. C-Phycocyanin, a selective cyclooxygenase-2 inhibitor, induces apoptosis in lipopolysaccharide-stimulated RAW 264.7 macrophages.

    PubMed

    Reddy, Madhava C; Subhashini, J; Mahipal, S V K; Bhat, Vadiraja B; Srinivas Reddy, P; Kiranmai, G; Madyastha, K M; Reddanna, P

    2003-05-02

    C-Phycocyanin (C-PC) is one of the major biliproteins of Spirulina platensis, a blue green algae, with antioxidant and radical scavenging properties. It is also known to exhibit anti-inflammatory and anti-cancer properties. However, the mechanism of action of C-PC is not clearly understood. Previously, we have shown that C-PC selectively inhibits cyclooxygenase-2 (COX-2), an inducible isoform that is upregulated during inflammation and cancer. In view of the reported induction of apoptosis in cancer cells by cyclooxygenase-2 inhibitors, the present study is undertaken to test the effect of C-PC on LPS stimulated RAW 264.7 mouse macrophage cell line. These studies have shown a dose dependent reduction in the growth and multiplication of macrophage cell line by C-PC. This decrease in cell number appears to be mediated by C-PC induced apoptosis as evidenced by flow cytometric and confocal microscopic studies. Cells treated with 20 micro M C-PC showed typical nuclear condensation and 16.6% of cells in sub-G(o)/G(1) phase. These cells also showed DNA fragmentation in a dose dependent manner. The studies on poly(ADP ribose) polymerase (PARP) cleavage showed typical fragmentation pattern in C-PC treated cells. This C-PC induced apoptosis in RAW 264.7 cells appears to be mediated by the release of cytochrome c from mitochondria and independent of Bcl-2 expression. These effects of C-PC on RAW 264.7 cells may be due to reduced PGE(2) levels as a result of COX-2 inhibition.

  4. Triazaspirodimethoxybenzoyls as Selective Inhibitors of Mycobacterial Lipoamide Dehydrogenase

    SciTech Connect

    Bryk, Ruslana; Arango, Nancy; Venugopal, Aditya; Warren, J. David; Park, Yun-Hee; Patel, Mulchand S.; Lima, Christopher D.; Nathan, Carl

    2010-06-25

    Mycobacterium tuberculosis (Mtb) remains the leading single cause of death from bacterial infection. Here we explored the possibility of species-selective inhibition of lipoamide dehydrogenase (Lpd), an enzyme central to Mtb's intermediary metabolism and antioxidant defense. High-throughput screening of combinatorial chemical libraries identified triazaspirodimethoxybenzoyls as high-nanomolar inhibitors of Mtb's Lpd that were noncompetitive versus NADH, NAD{sup +}, and lipoamide and >100-fold selective compared to human Lpd. Efficacy required the dimethoxy and dichlorophenyl groups. The structure of an Lpd-inhibitor complex was resolved to 2.42 {angstrom} by X-ray crystallography, revealing that the inhibitor occupied a pocket adjacent to the Lpd NADH/NAD{sup +} binding site. The inhibitor did not overlap with the adenosine moiety of NADH/NAD{sup +} but did overlap with positions predicted to bind the nicotinamide rings in NADH and NAD{sup +} complexes. The dimethoxy ring occupied a deep pocket adjacent to the FAD flavin ring where it would block coordination of the NADH nicotinamide ring, while the dichlorophenyl group occupied a more exposed pocket predicted to coordinate the NAD{sup +} nicotinamide. Several residues that are not conserved between the bacterial enzyme and its human homologue were predicted to contribute both to inhibitor binding and to species selectivity, as confirmed for three residues by analysis of the corresponding mutant Mtb Lpd proteins. Thus, nonconservation of residues lining the electron-transfer tunnel in Mtb Lpd can be exploited for development of species-selective Lpd inhibitors.

  5. Triazaspirodimethoxybenzoyls as selective inhibitors of mycobacterial lipoamide dehydrogenase .

    PubMed

    Bryk, Ruslana; Arango, Nancy; Venugopal, Aditya; Warren, J David; Park, Yun-Hee; Patel, Mulchand S; Lima, Christopher D; Nathan, Carl

    2010-03-02

    Mycobacterium tuberculosis (Mtb) remains the leading single cause of death from bacterial infection. Here we explored the possibility of species-selective inhibition of lipoamide dehydrogenase (Lpd), an enzyme central to Mtb's intermediary metabolism and antioxidant defense. High-throughput screening of combinatorial chemical libraries identified triazaspirodimethoxybenzoyls as high-nanomolar inhibitors of Mtb's Lpd that were noncompetitive versus NADH, NAD(+), and lipoamide and >100-fold selective compared to human Lpd. Efficacy required the dimethoxy and dichlorophenyl groups. The structure of an Lpd-inhibitor complex was resolved to 2.42 A by X-ray crystallography, revealing that the inhibitor occupied a pocket adjacent to the Lpd NADH/NAD(+) binding site. The inhibitor did not overlap with the adenosine moiety of NADH/NAD(+) but did overlap with positions predicted to bind the nicotinamide rings in NADH and NAD(+) complexes. The dimethoxy ring occupied a deep pocket adjacent to the FAD flavin ring where it would block coordination of the NADH nicotinamide ring, while the dichlorophenyl group occupied a more exposed pocket predicted to coordinate the NAD(+) nicotinamide. Several residues that are not conserved between the bacterial enzyme and its human homologue were predicted to contribute both to inhibitor binding and to species selectivity, as confirmed for three residues by analysis of the corresponding mutant Mtb Lpd proteins. Thus, nonconservation of residues lining the electron-transfer tunnel in Mtb Lpd can be exploited for development of species-selective Lpd inhibitors.

  6. Regulation of COX-2 expression by miR-146a in lung cancer cells.

    PubMed

    Cornett, Ashley L; Lutz, Carol S

    2014-09-01

    Prostaglandins are a class of molecules that mediate cellular inflammatory responses and control cell growth. The oxidative conversion of arachidonic acid to prostaglandin H2 is carried out by two isozymes of cyclooxygenase, COX-1 and COX-2. COX-1 is constitutively expressed, while COX-2 can be transiently induced by external stimuli, such as pro-inflammatory cytokines. Interestingly, COX-2 is overexpressed in numerous cancers, including lung cancer. MicroRNAs (miRNAs) are small RNA molecules that function to regulate gene expression. Previous studies have implicated an important role for miRNAs in human cancer. We demonstrate here that miR-146a expression levels are significantly lower in lung cancer cells as compared with normal lung cells. Conversely, lung cancer cells have higher levels of COX-2 protein and mRNA expression. Introduction of miR-146a can specifically ablate COX-2 protein and the biological activity of COX-2 as measured by prostaglandin production. The regulation of COX-2 by miR-146a is mediated through a single miRNA-binding site present in the 3' UTR. Therefore, we propose that decreased miR-146a expression contributes to the up-regulation and overexpression of COX-2 in lung cancer cells. Since potential miRNA-mediated regulation is a functional consequence of alternative polyadenylation site choice, understanding the molecular mechanisms that regulate COX-2 mRNA alternative polyadenylation and miRNA targeting will give us key insights into how COX-2 expression is involved in the development of a metastatic condition.

  7. Human airway smooth muscle cells secrete amphiregulin via bradykinin/COX-2/PGE2, inducing COX-2, CXCL8, and VEGF expression in airway epithelial cells

    PubMed Central

    Knox, Alan J.

    2015-01-01

    Human airway smooth muscle cells (HASMC) contribute to asthma pathophysiology through an increased smooth muscle mass and elevated cytokine/chemokine output. Little is known about how HASMC and the airway epithelium interact to regulate chronic airway inflammation and remodeling. Amphiregulin is a member of the family of epidermal growth factor receptor (EGFR) agonists with cell growth and proinflammatory roles and increased expression in the lungs of asthma patients. Here we show that bradykinin (BK) stimulation of HASMC increases amphiregulin secretion in a mechanism dependent on BK-induced COX-2 expression, increased PGE2 output, and the stimulation of HASMC EP2 and EP4 receptors. Conditioned medium from BK treated HASMC induced CXCL8, VEGF, and COX-2 mRNA and protein accumulation in airway epithelial cells, which were blocked by anti-amphiregulin antibodies and amphiregulin siRNA, suggesting a paracrine effect of HASMC-derived amphiregulin on airway epithelial cells. Consistent with this, recombinant amphiregulin induced CXCL8, VEGF, and COX-2 in airway epithelial cells. Finally, we found that conditioned media from amphiregulin-stimulated airway epithelial cells induced amphiregulin expression in HASMC and that this was dependent on airway epithelial cell COX-2 activity. Our study provides evidence of a dynamic axis of interaction between HASMC and epithelial cells that amplifies CXCL8, VEGF, COX-2, and amphiregulin production. PMID:26047642

  8. Refined homology model of monoacylglycerol lipase: toward a selective inhibitor

    NASA Astrophysics Data System (ADS)

    Bowman, Anna L.; Makriyannis, Alexandros

    2009-11-01

    Monoacylglycerol lipase (MGL) is primarily responsible for the hydrolysis of 2-arachidonoylglycerol (2-AG), an endocannabinoid with full agonist activity at both cannabinoid receptors. Increased tissue 2-AG levels consequent to MGL inhibition are considered therapeutic against pain, inflammation, and neurodegenerative disorders. However, the lack of MGL structural information has hindered the development of MGL-selective inhibitors. Here, we detail a fully refined homology model of MGL which preferentially identifies MGL inhibitors over druglike noninhibitors. We include for the first time insight into the active-site geometry and potential hydrogen-bonding interactions along with molecular dynamics simulations describing the opening and closing of the MGL helical-domain lid. Docked poses of both the natural substrate and known inhibitors are detailed. A comparison of the MGL active-site to that of the other principal endocannabinoid metabolizing enzyme, fatty acid amide hydrolase, demonstrates key differences which provide crucial insight toward the design of selective MGL inhibitors as potential drugs.

  9. Celecoxib enhances the radiosensitivity of HCT116 cells in a COX-2 independent manner by up-regulating BCCIP

    PubMed Central

    Xu, Xiao-Ting; Hu, Wen-Tao; Zhou, Ju-Ying; Tu, Yu

    2017-01-01

    It has been reported that celecoxib, a cyclooxygenase-2 (COX-2)-selective nonsteroidal anti-inflammatory drug (NSAID), regulates the radiosensitivity of several cancer cells. BCCIP (BRCA2 and CDKN1A interacting protein) plays a critical role in maintaining the critical functions of p53 in tumor suppression and response to therapy. However, whether the effect of celecoxib on the radiosensitivity of colorectal cancer (CRC) cells is dependent on BCCIP is largely unclear. In this study, we found that celecoxib enhanced the radiosensitivity of HeLa (a human cervical carcinoma cell line), A549 (a human lung carcinoma cell line), and HCT116 cells (a human CRC cells line). Among these cells, COX-2 expression was undetected in HCT116 cells. Treatment with celecoxib significantly increased BCCIP expression in COX-2 negative HCT116 cells. Knockdown of BCCIP obviously abrogated the enhanced radiosensitivity of HCT116 cells induced by celecoxib. A combination of celecoxib and irradiation treatment induced much more γ-H2AX foci formation, higher levels of radiation injury-related proteins phosphorylation, G2/M arrest, apoptosis, and p53 and p21 expression, and lower levels of Cyclin B1 in HCT116 cells than those in cells treated with irradiation alone. However, these changes were undetected in BCCIP-silenced HCT116 cells. Therefore, these data suggest that BCCIP gene may be a radiosensitivity-related gene in CRC. Celecoxib affects the functions of p53 and inhibits the recovery from the irradiation-induced injury by up-regulating the expression of BCCIP, and subsequently regulates the expressions of genes such as p21 and Cyclin B1 to enhance the radiosensitivity of HCT116 cells in a COX-2 independent manner. PMID:28386336

  10. Discovery and SAR of PF-4693627, a potent, selective and orally bioavailable mPGES-1 inhibitor for the potential treatment of inflammation.

    PubMed

    Arhancet, Graciela B; Walker, Daniel P; Metz, Sue; Fobian, Yvette M; Heasley, Steven E; Carter, Jeffrey S; Springer, John R; Jones, Darin E; Hayes, Michael J; Shaffer, Alexander F; Jerome, Gina M; Baratta, Michael T; Zweifel, Ben; Moore, William M; Masferrer, Jaime L; Vazquez, Michael L

    2013-02-15

    Inhibition of mPGES-1, the terminal enzyme in the arachidonic acid/COX pathway to regulate the production of pro-inflammatory prostaglandin PGE2, is considered an attractive new therapeutic target for safe and effective anti-inflammatory drugs. The discovery of a novel series of orally active, selective benzoxazole piperidinecarboxamides as mPGES-1 inhibitors is described. Structure-activity optimization of lead 5 with cyclohexyl carbinols resulted in compound 12, which showed excellent in vitro potency and selectivity against COX-2, and reasonable pharmacokinetic properties. Further SAR studies of the benzoxazole ring substituents lead to a novel series of highly potent compounds with improved PK profile, including 23, 26, and 29, which were effective in a carrageenan-stimulated guinea pig air pouch model of inflammation. Based on its excellent in vitro and in vivo pharmacological, pharmacokinetic and safety profile and ease of synthesis, compound 26 (PF-4693627) was advanced to clinical studies.

  11. Ribosome-Associated Mba1 Escorts Cox2 from Insertion Machinery to Maturing Assembly Intermediates

    PubMed Central

    Lorenzi, Isotta; Oeljeklaus, Silke; Ronsör, Christin; Bareth, Bettina; Warscheid, Bettina; Dennerlein, Sven

    2016-01-01

    The three conserved core subunits of the cytochrome c oxidase are encoded by mitochondria in close to all eukaryotes. The Cox2 subunit spans the inner membrane twice, exposing the N and C termini to the intermembrane space. For this, the N terminus is exported cotranslationally by Oxa1 and subsequently undergoes proteolytic maturation in Saccharomyces cerevisiae. Little is known about the translocation of the C terminus, but Cox18 has been identified to be a critical protein in this process. Here we find that the scaffold protein Cox20, which promotes processing of Cox2, is in complex with the ribosome receptor Mba1 and translating mitochondrial ribosomes in a Cox2-dependent manner. The Mba1-Cox20 complex accumulates when export of the C terminus of Cox2 is blocked by the loss of the Cox18 protein. While Cox20 engages with Cox18, Mba1 is no longer present at this stage. Our analyses indicate that Cox20 associates with nascent Cox2 and Mba1 to promote Cox2 maturation cotranslationally. We suggest that Mba1 stabilizes the Cox20-ribosome complex and supports the handover of Cox2 to the Cox18 tail export machinery. PMID:27550809

  12. New Insights on COX-2 in Chronic Inflammation Driving Breast Cancer Growth and Metastasis.

    PubMed

    Hugo, Honor J; Saunders, C; Ramsay, R G; Thompson, E W

    2015-12-01

    The medicinal use of aspirin stretches back to ancient times, before it was manufactured in its pure form in the late 19th century. Its accepted mechanistic target, cyclooxygenase (COX), was discovered in the 1970s and since this landmark discovery, the therapeutic application of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has increased dramatically. The most significant benefits of NSAIDs are in conditions involving chronic inflammation (CI). Given the recognized role of CI in cancer development, the use of long-term NSAID treatment in the prevention of cancer is an enticing possibility. COX-2 is a key driver of CI, and here we review COX-2 expression as a predictor of survival in various cancer types, including breast. Obesity and post-partum involution are natural inflammatory states that are associated with increased breast cancer risk. We outline the COX-2 mediated mechanisms contributing to the growth of cancers. We dissect the cellular mechanism of epithelial-mesenchymal transition (EMT) and how COX-2 may induce this to facilitate tumor progression. Finally we examine the potential regulation of COX-2 by c-Myb, and the possible interplay between c-Myb/COX-2 in proliferation, and hypoxia inducible factor-1 alpha (HIF1α)/COX-2 in invasive pathways in breast cancer.

  13. Synthesis and Evaluation of Carbaborane Derivatives of Indomethacin as Cyclooxygenase Inhibitors

    PubMed Central

    Scholz, Matthias; Blobaum, Anna L.; Marnett, Lawrence J.; Hey-Hawkins, Evamarie

    2011-01-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) exert their pharmacological activities by inhibiting cyclooxygenase (COX)-1 and COX-2. Previous studies have shown that esters and amides of non-selective inhibitors such as indomethacin are selective against COX-2, which is the therapeutically relevant isoform. Structure-activity analysis indicates that substituted phenyl rings are tolerated as ester components. In the present study, the introduction of inorganic ortho- and meta-carbaborane moieties was explored with the aim to create COX-2 inhibitors and more importantly to investigate the validity of using these boron clusters as drug entities. Interestingly, only the ortho-carbaborane ester was active whereas the meta isomer was not. A similar lack of inhibitory potency was observed when an adamantyl substituent or alkylene spacers at the carbaborane were introduced in the ester functionality. PMID:21524587

  14. The effect of celecoxib and its combination with imatinib on human HT-29 colorectal cancer cells: Involvement of COX-2, Caspase-3, VEGF and NF-κB genes expression.

    PubMed

    Atari-Hajipirloo, S; Nikanfar, S; Heydari, A; Noori, F; Kheradmand, F

    2016-02-29

    It has been shown that combination of imatinib (IM) with other agents may have some advantages in avoiding toxicity and resistance caused by this drug. The selective cyclooxygenase-2 inhibitor, celecoxib (CX), has been known to have antitumor and chemo-sensitizing effect in the treatment of colorectal cancer. In this study, we investigated the effectiveness of CX and its combination with anticancer agent IM on human colorectal cancer HT-29 cell and their probable molecular targets. Cultured HT-29 cells were exposed to IC50 dose of CX, IM, and their combination (half dose of IC50) for 24 hours to assess their effect on proliferation inhibition by MTT assay. The caspase-3 activity was estimated in HT-29 cells with colorimetric kit. COX-2, Caspase-3, VEGF and NF-κB genes expression was also investigated using real-time PCR method. Combined treatment with IM and CX, resulted in a significant (P˂0.05) decrease in cell viability and increased caspase-3 enzyme activity. Decreased COX-2 gene expression has been found in CX and combined treated group. Significant increase in Caspase-3 gene expression has been shown in IM and combined treated cells. In conclusion, the present in vitro study with colon cancer cell line demonstrated that CX and its combination with IM improved the anticancer activity of each component. Caspase-3 and COX-2 dependent molecular targets seem to be involved in mediating the anti-proliferative effects of IM and CX combination. Of course, the other molecular pathways are also likely to play the role and should be explored in future studies.

  15. SAR156497, an exquisitely selective inhibitor of aurora kinases.

    PubMed

    Carry, Jean-Christophe; Clerc, François; Minoux, Hervé; Schio, Laurent; Mauger, Jacques; Nair, Anil; Parmantier, Eric; Le Moigne, Ronan; Delorme, Cécile; Nicolas, Jean-Paul; Krick, Alain; Abécassis, Pierre-Yves; Crocq-Stuerga, Véronique; Pouzieux, Stéphanie; Delarbre, Laure; Maignan, Sébastien; Bertrand, Thomas; Bjergarde, Kirsten; Ma, Nina; Lachaud, Sylvette; Guizani, Houlfa; Lebel, Rémi; Doerflinger, Gilles; Monget, Sylvie; Perron, Sébastien; Gasse, Francis; Angouillant-Boniface, Odile; Filoche-Rommé, Bruno; Murer, Michel; Gontier, Sylvie; Prévost, Céline; Monteiro, Marie-Line; Combeau, Cécile

    2015-01-08

    The Aurora family of serine/threonine kinases is essential for mitosis. Their crucial role in cell cycle regulation and aberrant expression in a broad range of malignancies have been demonstrated and have prompted intensive search for small molecule Aurora inhibitors. Indeed, over 10 of them have reached the clinic as potential anticancer therapies. We report herein the discovery and optimization of a novel series of tricyclic molecules that has led to SAR156497, an exquisitely selective Aurora A, B, and C inhibitor with in vitro and in vivo efficacy. We also provide insights into its mode of binding to its target proteins, which could explain its selectivity.

  16. Expression of HuR, COX-2, and survivin in lung cancers; cytoplasmic HuR stabilizes cyclooxygenase-2 in squamous cell carcinomas.

    PubMed

    Kim, Gou Young; Lim, Sung-Jig; Kim, Youn Wha

    2011-10-01

    Hu antigen R (HuR) is a member of the human family of embryonic-lethal, abnormal vision-like proteins, which serves as an mRNA-binding protein. In the cytoplasm, HuR can stabilize the mRNA of cyclooxygenase-2 (COX-2), an enzyme that catalyses the synthesis of prostaglandins and is associated with promotion of carcinogenesis and tumor cell resistance to apoptosis. Intracellular (cytoplasmic and nuclear) localization of survivin has a prognostic significance as an apoptosis inhibitor and a regulator of cell division in tumors. Patients with 151 squamous cell carcinomas and 93 adenocarcinomas underwent lobectomy or pneumonectomy with hilar and mediastinal lymph node sampling. Paraffin-embedded tumor sections were retrieved for evaluation of nuclear and cytoplasmic staining of survivin and HuR, and cytoplasmic staining of COX-2. In squamous cell carcinomas, COX-2 expression was correlated with a difference of survivin (cytoplasmic-nuclear; P=0.004), cytoplasmic HuR (P=0.018), total HuR (cytoplasmic+nuclear; P=0.009), and difference of HuR (P=0.020). COX-2 was inversely correlated with nuclear survivin (P=0.006). In a univariate analysis by log-rank test, survival was associated with cytoplasmic survivin (adenocarcinoma, P<0.001; squamous cell carcinoma, P=0.005), difference of survivin (adenocarcinoma, P<0.001; squamous cell carcinoma, P=0.014), and COX-2 (squamous cell carcinoma, P=0.001). Survival was inversely associated with nuclear survivin (adenocarcinoma, P=0.006, squamous cell carcinoma, P=0.014). In a multivariate survival analysis, cytoplasmic survivin (adenocarcinoma, P=0.002; squamous cell carcinoma, P=0.015) and COX-2 (squamous cell carcinoma, P=0.020) were determined as independent prognostic factors. Cytoplasmic HuR expression is associated with COX-2 expression in squamous cell carcinomas. The expression of COX-2 in squamous cell carcinomas, and cytoplasmic survivin in adenocarcinomas and squamous cell carcinomas could be useful independent prognostic

  17. Mono-, di-, and triaryl substituted tetrahydropyrans as cyclooxygenase-2 and tumor growth inhibitors. Synthesis and biological evaluation.

    PubMed

    Singh, Palwinder; Bhardwaj, Atul

    2010-05-13

    Rationally designed tetrahydropyrans (THPs) carrying one, two, or three aryl rings and other substituents were synthesized by the allylation of beta-hydroxy ketones followed by iodocyclization. It has been observed that compounds with one aryl ring on THP are moderate inhibitors of cyclooxygenase-1 (COX-1) (IC(50) = 0.3 microM) and cyclooxygenase-2 (IC(50) = 0.17 microM) with poor selectivity index (SI = 2-3) for COX-2. The presence of two aryl rings enhanced their inhibitory activities for COX-2 (IC(50) = 0.9-5.5 nM). Selectivity for COX-2 over COX-1 also increased (SI = 50-1900), while triaryl substituted THPs, along with high inhibition (IC(50) = 0.57-4.0 nM), also exhibited excellent selectivity for COX-2 over COX-1 (SI = 3200-44000). Similar to the experimental results of increased COX-2 inhibition and selectivity with the increase in the size of the molecule, their docking in the active sites of COX-1 and COX-2 also showed same trend. Seven compounds from the category of di- and triaryl substituted THPs exhibited average GI(50) over all the human tumor cell lines in the range 1.6-3.2 microM and showed in vitro therapeutic indices of 8-17.

  18. miR-143 decreases COX-2 mRNA stability and expression in pancreatic cancer cells

    SciTech Connect

    Pham, Hung; Ekaterina Rodriguez, C.; Donald, Graham W.; Hertzer, Kathleen M.; Jung, Xiaoman S.; Chang, Hui-Hua; Moro, Aune; Reber, Howard A.; Hines, O. Joe; Eibl, Guido

    2013-09-13

    Highlights: •Pancreatic cancer cells express low miR-143 levels and elevated p-MEK, p-MAPK and RREB1. •MEK inhibitors U0126 and PD98059 increase miR-143 expression. •miR-143 decreases COX-2 mRNA stability and expression and PGE{sub 2}. •miR-143 decreases p-p38MAPK, p-MEK, p-MAPK and RREB1 expression. -- Abstract: Small non-coding RNAs, microRNAs (miRNA), inhibit the translation or accelerate the degradation of message RNA (mRNA) by targeting the 3′-untranslated region (3′-UTR) in regulating growth and survival through gene suppression. Deregulated miRNA expression contributes to disease progression in several cancers types, including pancreatic cancers (PaCa). PaCa tissues and cells exhibit decreased miRNA, elevated cyclooxygenase (COX)-2 and increased prostaglandin E{sub 2} (PGE{sub 2}) resulting in increased cancer growth and metastases. Human PaCa cell lines were used to demonstrate that restoration of miRNA-143 (miR-143) regulates COX-2 and inhibits cell proliferation. miR-143 were detected at fold levels of 0.41 ± 0.06 in AsPC-1, 0.20 ± 0.05 in Capan-2 and 0.10 ± 0.02 in MIA PaCa-2. miR-143 was not detected in BxPC-3, HPAF-II and Panc-1 which correlated with elevated mitogen-activated kinase (MAPK) and MAPK kinase (MEK) activation. Treatment with 10 μM of MEK inhibitor U0126 or PD98059 increased miR-143, respectively, by 187 ± 18 and 152 ± 26-fold in BxPC-3 and 182 ± 7 and 136 ± 9-fold in HPAF-II. miR-143 transfection diminished COX-2 mRNA stability at 60 min by 2.6 ± 0.3-fold in BxPC-3 and 2.5 ± 0.2-fold in HPAF-II. COX-2 expression and cellular proliferation in BxPC-3 and HPAF-II inversely correlated with increasing miR-143. PGE{sub 2} levels decreased by 39.3 ± 5.0% in BxPC-3 and 48.0 ± 3.0% in HPAF-II transfected with miR-143. Restoration of miR-143 in PaCa cells suppressed of COX-2, PGE{sub 2}, cellular proliferation and MEK/MAPK activation, implicating this pathway in regulating miR-143 expression.

  19. Uncovering Molecular Bases Underlying Bone Morphogenetic Protein Receptor Inhibitor Selectivity

    PubMed Central

    Alsamarah, Abdelaziz; LaCuran, Alecander E.; Oelschlaeger, Peter; Hao, Jijun; Luo, Yun

    2015-01-01

    Abnormal alteration of bone morphogenetic protein (BMP) signaling is implicated in many types of diseases including cancer and heterotopic ossifications. Hence, small molecules targeting BMP type I receptors (BMPRI) to interrupt BMP signaling are believed to be an effective approach to treat these diseases. However, lack of understanding of the molecular determinants responsible for the binding selectivity of current BMP inhibitors has been a big hindrance to the development of BMP inhibitors for clinical use. To address this issue, we carried out in silico experiments to test whether computational methods can reproduce and explain the high selectivity of a small molecule BMP inhibitor DMH1 on BMPRI kinase ALK2 vs. the closely related TGF-β type I receptor kinase ALK5 and vascular endothelial growth factor receptor type 2 (VEGFR2) tyrosine kinase. We found that, while the rigid docking method used here gave nearly identical binding affinity scores among the three kinases; free energy perturbation coupled with Hamiltonian replica-exchange molecular dynamics (FEP/H-REMD) simulations reproduced the absolute binding free energies in excellent agreement with experimental data. Furthermore, the binding poses identified by FEP/H-REMD led to a quantitative analysis of physical/chemical determinants governing DMH1 selectivity. The current work illustrates that small changes in the binding site residue type (e.g. pre-hinge region in ALK2 vs. ALK5) or side chain orientation (e.g. Tyr219 in caALK2 vs. wtALK2), as well as a subtle structural modification on the ligand (e.g. DMH1 vs. LDN193189) will cause distinct binding profiles and selectivity among BMP inhibitors. Therefore, the current computational approach represents a new way of investigating BMP inhibitors. Our results provide critical information for designing exclusively selective BMP inhibitors for the development of effective pharmacotherapy for diseases caused by aberrant BMP signaling. PMID:26133550

  20. Anilino-monoindolylmaleimides as potent and selective JAK3 inhibitors.

    PubMed

    McDonnell, Mark E; Bian, Haiyan; Wrobel, Jay; Smith, Garry R; Liang, Shuguang; Ma, Haiching; Reitz, Allen B

    2014-02-15

    We designed a series of anilino-indoylmaleimides based on structural elements from literature JAK3 inhibitors 3 and 4, and our lead 5. These new compounds were tested as inhibitors of JAKs 1, 2 and 3 and TYK2 for therapeutic intervention in rheumatoid arthritis (RA). Our requirements, based on current scientific rationale for optimum efficacy against RA with reduced side effects, was for potent, mixed JAK1 and 3 inhibition, and selectivity over JAK2. Our efforts yielded a potent JAK3 inhibitor 11d and its eutomer 11e. These compounds were highly selective for inhibition of JAK3 over JAK2 and TYK. The compounds displayed only modest JAK1 inhibition.

  1. Discovery of potent, selective chymase inhibitors via fragment linking strategies.

    PubMed

    Taylor, Steven J; Padyana, Anil K; Abeywardane, Asitha; Liang, Shuang; Hao, Ming-Hong; De Lombaert, Stéphane; Proudfoot, John; Farmer, Bennett S; Li, Xiang; Collins, Brandon; Martin, Leslie; Albaugh, Daniel R; Hill-Drzewi, Melissa; Pullen, Steven S; Takahashi, Hidenori

    2013-06-13

    Chymase plays an important and diverse role in the homeostasis of a number of cardiovascular processes. Herein, we describe the identification of potent, selective chymase inhibitors, developed using fragment-based, structure-guided linking and optimization techniques. High-concentration biophysical screening methods followed by high-throughput crystallography identified an oxindole fragment bound to the S1 pocket of the protein exhibiting a novel interaction pattern hitherto not observed in chymase inhibitors. X-ray crystallographic structures were used to guide the elaboration/linking of the fragment, ultimately leading to a potent inhibitor that was >100-fold selective over cathepsin G and that mitigated a number of liabilities associated with poor physicochemical properties of the series it was derived from.

  2. Hydrogen sulfide promotes cell proliferation of oral cancer through activation of the COX2/AKT/ERK1/2 axis.

    PubMed

    Zhang, Shuai; Bian, Huan; Li, Xiaoxu; Wu, Huanhuan; Bi, Qingwei; Yan, Yingbin; Wang, Yixiang

    2016-05-01

    Hydrogen sulfide, the third gaseous transmitter, is one of the main causes of halitosis in the oral cavity. It is generally considered as playing a deleterious role in many oral diseases including oral cancer. However, the regulatory mechanisms involved in the effects of hydrogen sulfide on oral cancer growth remain largely unknown. In the present study, we investigated the underlying mechanisms through CCK-8 assay, EdU incorporation, real-time PCR, western blot and pathway blockade assays. Our results showed that hydrogen sulfide promoted oral cancer cell proliferation through activation of the COX2, AKT and ERK1/2 pathways in a dose-dependent manner. Blocking any of the three above pathways inhibited hydrogen sulfide-induced oral cancer cell proliferation. Meanwhile, blockade of COX2 by niflumic acid downregulated NaHS-induced p-ERK and p-AKT expression. Inactivation of the AKT pathway by GSK690693 significantly decreased NaHS‑induced p-ERK1/2 expression, and inhibition of the ERK1/2 pathway by U0126 markedly increased NaHS-induced p-AKT expression. Either the AKT or ERK1/2 inhibitor did not significantly alter the COX2 expression level. Our data revealed, for the first time, that hydrogen sulfide promotes oral cancer cell proliferation through activation of the COX2/AKT/ERK1/2 axis, suggesting new potential targets to eliminate the effect of hydrogen sulfide on the development of oral cancer.

  3. Up-regulated neuronal COX-2 expression after cortical spreading depression is involved in non-REM sleep induction in rats.

    PubMed

    Cui, Yilong; Kataoka, Yosky; Inui, Takashi; Mochizuki, Takatoshi; Onoe, Hirotaka; Matsumura, Kiyoshi; Urade, Yoshihiro; Yamada, Hisao; Watanabe, Yasuyoshi

    2008-03-01

    Cortical spreading depression is an excitatory wave of depolarization spreading throughout cerebral cortex at a rate of 2-5 mm/min and has been implicated in various neurological disorders, such as epilepsy, migraine aura, and trauma. Although sleepiness or sleep is often induced by these neurological disorders, the cellular and molecular mechanism has remained unclear. To investigate whether and how the sleep-wake behavior is altered by such aberrant brain activity, we induced cortical spreading depression in freely moving rats, monitoring REM and non-REM (NREM) sleep and sleep-associated changes in cyclooxygenase (COX)-2 and prostaglandins (PGs). In such a model for aberrant neuronal excitation in the cerebral cortex, the amount of NREM sleep, but not of REM sleep, increased subsequently for several hours, with an up-regulated expression of COX-2 in cortical neurons and considerable production of PGs. A specific inhibitor of COX-2 completely arrested the increase in NREM sleep. These results indicate that up-regulated neuronal COX-2 would be involved in aberrant brain excitation-induced NREM sleep via production of PGs.

  4. COX-1 and COX-2 expression in feline oral squamous cell carcinoma.

    PubMed

    Hayes, A; Scase, T; Miller, J; Murphy, S; Sparkes, A; Adams, V

    2006-01-01

    This study demonstrated immunohistochemically the expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) in feline oral squamous cell carcinoma (FOSCC), with primary polyclonal antibodies raised against human epitopes. COX-2 immunolabelling was intracytoplasmic and, in some neoplastic cells, perinuclear; it was demonstrated in a small proportion (< or = 1%) of neoplastic cells and its intensity was usually mild to moderate. In contrast, all neoplastic tissues showed extensive nuclear and cytoplasmic COX-1 immunolabelling. Cytoplasmic COX-1 immunolabelling was less intense than nuclear labelling in neoplastic tissue. In the adjacent histologically normal oral mucosa, COX-2 immunolabelling was absent. The cytoplasmic and nuclear intensity and distribution of COX-1 immunolabelling was significantly higher in neoplastic tissue than in adjacent normal oral mucosa. The results indicate that COX-1 and COX-2 are overexpressed in FOSCC, but the clinical and pathophysiological significance of this finding remains to be determined.

  5. COX-2 expression induced by diesel particles involves chromatin modification and degradation of HDAC1

    EPA Science Inventory

    Cyclooxygenase-2 (COX-2) plays an important role in the inflammatory response induced by physiologic and stress stimuli. Exposure to diesel exhaust particulate matter (DEP) has been shown to induce pulmonary inflammation and exacerbate asthma and chronic obstructive pulmonary dis...

  6. Pro-inflammatory Signaling in a 3D Organotypic Skin Model after Low LET Irradiation—NF-κB, COX-2 Activation, and Impact on Cell Differentiation

    PubMed Central

    Acheva, Anna; Schettino, Giuseppe; Prise, Kevin M.

    2017-01-01

    Nearly 85% of radiotherapy patients develop acute radiation dermatitis, which is an inflammatory reaction of the skin at the treatment field and in the surrounding area. The aims of this study were to unravel the mechanisms of radiation-induced inflammatory responses after localized irradiation in a human 3D organotypic skin culture model. This could provide possible inflammatory targets for reduction of skin side effects. 3D organotypic skin cultures were set up and locally irradiated with 225 kVp X-rays, using a combination of full exposure and partial shielding (50%) of the cultures. The secretion of pro-inflammatory cytokines, the phenotype, and the differentiation markers expression of the cultures were assessed up to 10 days postirradiation. The pro-inflammatory transcription factor nuclear factor kappa B (NF-κB) and cyclooxygenase-2 (COX-2) pathways have been studied. The results showed fast activation of NF-κB, most likely triggered by DNA damage in the irradiated cells, followed by upregulation of p38 MAPK and COX-2 in the irradiated and surrounding, non-irradiated, areas of the 3D cultures. The application of the COX-2 inhibitor sc-236 was effective at reducing the COX-2 mRNA levels 4 h postirradiation. The same inhibitor also suppressed the PGE2 secretion significantly 72 h after the treatment. The expression of a pro-inflammatory phenotype and abnormal differentiation markers of the cultures were also reduced. However, the use of an NF-κB inhibitor (Bay 11-7085) did not have the predicted positive effect on the cultures phenotype postirradiation. Radiation-induced pro-inflammatory responses have been observed in the 3D skin model. The activated signaling pathways involved NF-κB transcription factor and its downstream target COX-2. Further experiments aiming to suppress the inflammatory response via specific inhibitors showed that COX-2 is a suitable target for reduction of the normal skin inflammatory responses at radiotherapy, while NF

  7. Pro-inflammatory Signaling in a 3D Organotypic Skin Model after Low LET Irradiation-NF-κB, COX-2 Activation, and Impact on Cell Differentiation.

    PubMed

    Acheva, Anna; Schettino, Giuseppe; Prise, Kevin M

    2017-01-01

    Nearly 85% of radiotherapy patients develop acute radiation dermatitis, which is an inflammatory reaction of the skin at the treatment field and in the surrounding area. The aims of this study were to unravel the mechanisms of radiation-induced inflammatory responses after localized irradiation in a human 3D organotypic skin culture model. This could provide possible inflammatory targets for reduction of skin side effects. 3D organotypic skin cultures were set up and locally irradiated with 225 kVp X-rays, using a combination of full exposure and partial shielding (50%) of the cultures. The secretion of pro-inflammatory cytokines, the phenotype, and the differentiation markers expression of the cultures were assessed up to 10 days postirradiation. The pro-inflammatory transcription factor nuclear factor kappa B (NF-κB) and cyclooxygenase-2 (COX-2) pathways have been studied. The results showed fast activation of NF-κB, most likely triggered by DNA damage in the irradiated cells, followed by upregulation of p38 MAPK and COX-2 in the irradiated and surrounding, non-irradiated, areas of the 3D cultures. The application of the COX-2 inhibitor sc-236 was effective at reducing the COX-2 mRNA levels 4 h postirradiation. The same inhibitor also suppressed the PGE2 secretion significantly 72 h after the treatment. The expression of a pro-inflammatory phenotype and abnormal differentiation markers of the cultures were also reduced. However, the use of an NF-κB inhibitor (Bay 11-7085) did not have the predicted positive effect on the cultures phenotype postirradiation. Radiation-induced pro-inflammatory responses have been observed in the 3D skin model. The activated signaling pathways involved NF-κB transcription factor and its downstream target COX-2. Further experiments aiming to suppress the inflammatory response via specific inhibitors showed that COX-2 is a suitable target for reduction of the normal skin inflammatory responses at radiotherapy, while NF

  8. Cardiac Toxicity in Selective Serotonin Reuptake Inhibitor Users.

    PubMed

    Lusetti, Monia; Licata, Manuela; Silingardi, Enrico; Reggiani Bonetti, Luca; Palmiere, Cristian

    2015-12-01

    Several classes of recreational and prescription drugs have been associated with an increased risk of cardiovascular disease and the occurrence of arrhythmias, which may be involved in sudden deaths in chronic users even at therapeutic doses. The study presented herein focuses on pathological changes involving the heart, which may be caused by selective serotonin reuptake inhibitor use and their possible role in the occurrence of sudden cardiac death. A total of 40 cases were included in the study and were divided evenly into 2 groups: 20 cases of patients treated with selective serotonin reuptake inhibitors and 20 cases of sudden deaths involving patients void of any drug treatment. The first group included 16 patients treated with citalopram and 4 with sertraline. Autopsies, histology, biochemistry, and toxicology were performed in all cases. Pathological changes in selective serotonin reuptake inhibitor users consisted of various degrees of interstitial and perivascular fibrosis as well as a small degree of perineural fibrosis within the myocardium of the left ventricle. Within the limits of the small number of investigated cases, the results of this study seem to confirm former observations on this topic, suggesting that selective serotonin reuptake inhibitors may play a potential, causative role in the pathogenesis of sudden deaths in chronic users even at therapeutic concentrations.

  9. Selective serotonin reuptake inhibitors for depression in pregnancy.

    PubMed

    Susser, Leah C; Sansone, Stephanie A; Hermann, Alison D

    2016-12-01

    Perinatal depression is associated with a high risk of morbidity and mortality and may have long-term consequences on child development. The US Preventive Services Task Force has recently recognized the importance of identifying and treating women with depression in the perinatal period. However, screening and accessing appropriate treatment come with logistical challenges. In many areas, there may not be sufficient access to psychiatric care, and, until these resources develop, the burden may inadvertently fall on obstetricians. As a result, understanding the risks of perinatal depression in comparison with the risks of treatment is important. Many studies of selective serotonin reuptake inhibitors in pregnancy fail to control for underlying depressive illness, which can lead to misinterpretation of selective serotonin reuptake inhibitor risk by clinicians. This review discusses the risks and benefits of selective serotonin reuptake inhibitor treatment in pregnancy within the context of perinatal depression. Whereas selective serotonin reuptake inhibitors may be associated with certain risks, the absolute risks are low and may be outweighed by the risks of untreated depression for many women and their offspring.

  10. Expression of COX-2 and Bcl-2 in primary fallopian tube carcinoma: correlations with clinicopathologic features.

    PubMed

    Wang, Fang; Sun, Guo-Ping; Zou, Yan-Feng; Wu, Qiang; Wu, Hong-Yang; Wu, Ji-Feng; Zhou, Jia-De; Chen, Ke; Zhang, Xiu-Shan

    2011-01-01

    The aim of this study was to evaluate the expression of COX-2 and Bcl-2 in primary fallopian tube carcinoma (PFTC), as well as their correlations with clinicopathologic features. We studied a cohort of 33 patients with a pathological diagnosis of PFTC. Thirty normal tubal tissues used for controls were obtained from patients diagnosed with uterine myomas. Expression analysis for COX-2 and Bcl-2 was performed using the immunohistochemical technique. The rate of preoperative diagnosis was 18.2%. With a median survival of 61.0 months (95% CI: 43.2 to 78.8 months), the estimated five-year overall survival rate in the 33 patients was 39.0%. Increased expression of COX-2 and Bcl-2 was observed in tumor specimens compared to normal controls (p = 0.026; p = 0.003). The expression rate of COX-2 in node-positive tumors was significantly higher than that of node-negative tumors (p = 0.024). Moreover, the expression rate of COX-2 was statistically significantly higher in patients with infiltration through the serosa (p = 0.019). Positive significant associations were observed between Bcl-2 staining index and FIGO stage (p = 0.015), and between Bcl-2 staining and lymph node metastasis (p = 0.010). There was a significant correlation between COX-2 expression and Bcl-2 staining index (r = 0.517, p = 0.002). We conclude that COX-2 and Bcl-2 may potentially be useful prognostic markers for PFTC. The exact molecular mechanism for correlations between COX-2 and Bcl-2 remains to be elucidated.

  11. Odontogenic epithelial proliferation is correlated with COX-2 expression in dentigerous cyst and ameloblastoma

    PubMed Central

    Alsaegh, Mohammed Amjed; Miyashita, Hitoshi; Taniguchi, Takahiro; Zhu, Sheng Rong

    2017-01-01

    Investigation of cyclooxygenase (COX)-2 in dentigerous cyst and ameloblastoma may help to improve understanding of the nature and behavior of odontogenic cysts and tumors, and in addition may eventually represent a definitive target for a pharmacological approach in the management of these lesions. The aim of this study was to evaluate COX-2 expression and its correlation with the proliferation of odontogenic epithelium in these lesions. Dentigerous cysts (n=16) and ameloblastomas (n=17) were evaluated. Detection of Ki-67 and COX-2 protein expression was conducted by immunohistochemistry. Data were statistically analyzed using Mann-Whitney U test and Spearman's rank correlation coefficient. No significant differences were found in the expression of Ki-67 and COX-2 between dentigerous cysts and ameloblastomas (P>0.05). A significant positive correlation (P=0.018) and highly significant positive correlation (P=0.004) were found between Ki-67 and COX-2 expression in the odontogenic epithelium of dentigerous cyst and ameloblastoma, respectively. COX-2 was expressed in the odontogenic epithelium of dentigerous cyst and ameloblastoma. It may contribute to local extension of these lesions by increasing the proliferation of their odontogenic epithelial cells. PMID:28123497

  12. Reduced COX-2 Expression in Aged Mice Is Associated With Impaired Fracture Healing

    PubMed Central

    Naik, Amish A; Xie, Chao; Zuscik, Michael J; Kingsley, Paul; Schwarz, Edward M; Awad, Hani; Guldberg, Robert; Drissi, Hicham; Puzas, J Edward; Boyce, Brendan; Zhang, Xinping; O'Keefe, Regis J

    2009-01-01

    The cellular and molecular events responsible for reduced fracture healing with aging are unknown. Cyclooxygenase 2 (COX-2), the inducible regulator of prostaglandin E2 (PGE2) synthesis, is critical for normal bone repair. A femoral fracture repair model was used in mice at either 7–9 or 52–56 wk of age, and healing was evaluated by imaging, histology, and gene expression studies. Aging was associated with a decreased rate of chondrogenesis, decreased bone formation, reduced callus vascularization, delayed remodeling, and altered expression of genes involved in repair and remodeling. COX-2 expression in young mice peaked at 5 days, coinciding with the transition of mesenchymal progenitors to cartilage and the onset of expression of early cartilage markers. In situ hybridization and immunohistochemistry showed that COX-2 is expressed primarily in early cartilage precursors that co-express col-2. COX-2 expression was reduced by 75% and 65% in fractures from aged mice compared with young mice on days 5 and 7, respectively. Local administration of an EP4 agonist to the fracture repair site in aged mice enhanced the rate of chondrogenesis and bone formation to levels observed in young mice, suggesting that the expression of COX-2 during the early inflammatory phase of repair regulates critical subsequent events including chondrogenesis, bone formation, and remodeling. The findings suggest that COX-2/EP4 agonists may compensate for deficient molecular signals that result in the reduced fracture healing associated with aging. PMID:18847332

  13. The VEGFR2, COX-2 and MMP-2 polymorphisms are associated with clinical outcome of patients with inoperable non-small cell lung cancer.

    PubMed

    Butkiewicz, Dorota; Krześniak, Małgorzata; Drosik, Anna; Giglok, Monika; Gdowicz-Kłosok, Agnieszka; Kosarewicz, Agata; Rusin, Marek; Masłyk, Barbara; Gawkowska-Suwińska, Marzena; Suwiński, Rafał

    2015-11-15

    Certain common inherited variations in genes involved in tumor angiogenesis, progression and metastasis may contribute to cancer therapy outcome and prognosis by altering the gene expression and protein activity. In this report, we examined the effect of functional polymorphisms in MMP-1, MMP-2, MMP-3, VEGF, VEGFR2, FGFR4 and COX-2 genes on overall (OS) and progression-free survival (PFS) of 350 Caucasian patients with inoperable non-small cell lung cancer (NSCLC). The results of multivariate analysis indicated that VEGFR2 -906C and COX-2 -1195G alleles were strongly associated with poor OS and PFS (p = 0.002 and 0.015, respectively, for OS; p = 0.009 and 0.015, respectively, for PFS), while MMP-2 -1306 T allele carriers had significantly reduced PFS (p = 0.010). Moreover, an increased risk of death and progression was significantly associated with the number of adverse alleles for VEGFR2/COX-2 (p = 0.0005 for OS and 0.0006 for PFS in >1 adverse allele carriers) and VEGFR2/COX-2/MMP-2 combinations (p = 0.0003 for OS and 0.0001 for PFS in patients with >2 adverse alleles). Finally, VEGFR2 TC/CC, COX-2 AG/GG and MMP-2 CT/TT genotypes as well as "at risk" allele combinations were identified as independent predictors of unfavorable OS and PFS in the group. In conclusion, the data suggest that selected VEGFR2, COX-2 and MMP-2 polymorphisms may be potential prognostic markers in unresectable NSCLC treated with radiotherapy with or without chemotherapy, although further validation studies are warranted to confirm our observations.

  14. Safety of selective cyclooxygenase-2 inhibitors and a basic non-steroidal anti-inflammatory drug (NSAID) in Japanese patients with NSAID-induced urticaria and/or angioedema: Comparison of meloxicam, etodolac and tiaramide.

    PubMed

    Inomata, Naoko; Osuna, Hiroyuki; Yamaguchi, Junko; Onoda, Masahito; Takeshita, Yoshihiro; Chiba, Yoshiyuki; Kambara, Takeshi; Ikezawa, Zenro

    2007-03-01

    The identification of a safe and reliable alternative for patients with non-steroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema is a frequent problem for dermatologists and other practitioners. Cyclooxygenase-2 (COX-2) inhibitors have been reported to be safe for NSAID-intolerant patients from the US and Europe but not all of them have yet been approved for use in Japan. It was our objective to investigate the clinical manifestations of oral NSAID challenges in Japanese patients with histories of urticaria and/or angioedema after the intake of NSAIDs and to find safe alternative drugs, including COX-2 inhibitors and a basic anti-inflammatory drug. Twenty subjects suspected NSAID-induced urticaria/angioedema from histories were included in a double-blind or single-blind, placebo-controlled oral challenge protocol using NSAIDs. Skin prick tests using NSAIDs, which were dissolved in saline, were conducted. The mean age of the patients was 37.3 years; 14 patients were female. The results of other challenge tests showed that the most frequently intolerated drugs was loxoprofen (100%), followed by acetyl salicylic (94.4%), etodolac (53.3%), dicrofenac (50%), acetaminophen (38.5%), meloxicam (33%), and tiaramide (21.4%). Urticaria and angioedema were induced after aspirin intake in 83.3% and 22.2% of patients, respectively, whereas an asthmatic response was seen in 5.6%. Skin prick tests with NSAIDs were 100% negative. This study showed that among the NSAIDs that are available in Japan and that were investigated in this study, tiaramide, which does not inhibit COX, is the relatively safe alternative drug for Japanese patients with NSAID-induced urtiacaria and/or angioedema. Furthermore, meloxicam seems to be better tolerated than etodolac between two selective COX-2 inhibitors.

  15. Association of COX-2 Promoter Polymorphisms -765G/C and -1195A/G with Migraine

    PubMed Central

    MOZAFFARI, Elahe; DOOSTI, Abbas; ARSHI, Asghar; FAGHANI, Mostafa

    2016-01-01

    Background: Migraine is a common debilitating primary headache disorder with current head pain attacks, which contributes to physical activity dysfunctions in chronic pain phase. PGE2 and PGI2 are two important prostaglandins synthesised by COX-2 enzymes, involved in migraine pain signals. COX-2 modulation is essential in treatment and pathogenesis of migraine. This study aimed to investigating the association between COX-2 gene polymorphisms with the risk of migraine susceptibility in migraine patients with related and unrelated parents. Methods: This case- control study was based on 100 migraine patients and 100 non-migraine subjects in Bushehr province, Iran in 2013. Genomic DNA of blood samples was extracted and genotyping of COX-2-765G>C (rs20417) and COX-2-1195A>G (rs689466) gene variants was investigated by PCR-RFLP method. Statistical analyses were accomplished using the SPSS software package. Results: There was a significant differences in the frequencies of the COX-2-765G>C and COX-2-1195A>G genotypes between migraine patients and controls (P≤0.05). Conclusion: COX-2-765CC, COX-2-765CG, COX-2-1195GG and COX-2-1195AG genotypes can increase the risk of migraine significantly. As the first study in Iran, we are hopeful to achieve greater results about the relevancy of COX-2 gene, migraine and pain signals pathway by repeating these experiments on more samples. PMID:28053929

  16. DNA-linked Inhibitor Antibody Assay (DIANA) for sensitive and selective enzyme detection and inhibitor screening

    PubMed Central

    Navrátil, Václav; Schimer, Jiří; Tykvart, Jan; Knedlík, Tomáš; Vik, Viktor; Majer, Pavel; Konvalinka, Jan; Šácha, Pavel

    2017-01-01

    Human diseases are often diagnosed by determining levels of relevant enzymes and treated by enzyme inhibitors. We describe an assay suitable for both ultrasensitive enzyme quantification and quantitative inhibitor screening with unpurified enzymes. In the DNA-linked Inhibitor ANtibody Assay (DIANA), the target enzyme is captured by an immobilized antibody, probed with a small-molecule inhibitor attached to a reporter DNA and detected by quantitative PCR. We validate the approach using the putative cancer markers prostate-specific membrane antigen and carbonic anhydrase IX. We show that DIANA has a linear range of up to six logs and it selectively detects zeptomoles of targets in complex biological samples. DIANA's wide dynamic range permits determination of target enzyme inhibition constants using a single inhibitor concentration. DIANA also enables quantitative screening of small-molecule enzyme inhibitors using microliters of human blood serum containing picograms of target enzyme. DIANA's performance characteristics make it a superior tool for disease detection and drug discovery. PMID:27679479

  17. Coexpression of COX-2 and iNOS in Angiogenesis of Superficial Esophageal Squamous Cell Carcinoma.

    PubMed

    Kumagai, Youichi; Sobajima, Jun; Higashi, Morihiro; Ishiguro, Toru; Fukuchi, Minoru; Ishibashi, Keiichiro; Mochiki, Erito; Yakabi, Koji; Kawano, Tatsuyuki; Tamaru, Jun-ichi; Ishida, Hideyuki

    2015-04-01

    Using immunohistochemical staining, the present study was conducted to examine whether cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) affect angiogenesis in early-stage esophageal squamous cell carcinoma (ESCC). We also analyzed the correlation between these two factors. Cyclooxygenase 2, iNOS, and angiogenesis in early-stage ESCC are unclear. Using 10 samples of normal squamous epithelium, 7 samples of low-grade intraepithelial neoplasia (LGIN), and 45 samples of superficial esophageal cancer, we observed the expression of COX-2 and iNOS. We then investigated the COX-2 and iNOS immunoreactivity scores and the correlation between COX-2 or iNOS scores and microvessel density (MVD) using CD34 or CD105. The intensity of COX-2 or iNOS expression differed significantly according to histological type (P < 0.001). The scores of COX-2 and iNOS were lowest for normal squamous epithelium, followed in ascending order by LGIN, carcinoma in situ and tumor invading the lamina propria mucosae (M1-M2 cancer); and tumor invading the muscularis mucosa (M3) or deeper cancer. The differences were significant (P < 0.001). Cancers classified M1-M2 (P < 0.01 and P < 0.05, respectively); M3; or deeper cancer (P < 0.01) had significantly higher COX-2 and iNOS scores than normal squamous epithelium. There was a significant correlation between COX-2 and iNOS scores (P < 0.001, rs = 0.51). Correlations between COX-2 score and CD34-positive MVD or CD105-positive MVD were significant (rs = 0.53, P < 0.001; rs = 0.62, P < 0.001, respectively). Inducible nitric oxide synthase score was also significantly correlated with CD34 MVD and CD105 MVD (rs = 0.45, P < 0.001; rs = 0.60, P < 0.001, respectively). Chemoprevention of COX-2 or iNOS activity may blunt the development of ESCC from precancerous lesions.

  18. Selective Mycobacterium tuberculosis Shikimate Kinase Inhibitors as Potential Antibacterials

    PubMed Central

    Gordon, Sara; Simithy, Johayra; Goodwin, Douglas C; Calderón, Angela I

    2015-01-01

    Owing to the persistence of tuberculosis (TB) as well as the emergence of multidrug-resistant and extensively drug-resistant (XDR) forms of the disease, the development of new antitubercular drugs is crucial. Developing inhibitors of shikimate kinase (SK) in the shikimate pathway will provide a selective target for antitubercular agents. Many studies have used in silico technology to identify compounds that are anticipated to interact with and inhibit SK. To a much more limited extent, SK inhibition has been evaluated by in vitro methods with purified enzyme. Currently, there are no data on in vivo activity of Mycobacterium tuberculosis shikimate kinase (MtSK) inhibitors available in the literature. In this review, we present a summary of the progress of SK inhibitor discovery and evaluation with particular attention toward development of new antitubercular agents. PMID:25861218

  19. Altered arachidonic acid metabolism via COX-1 and COX-2 contributes to the endothelial dysfunction of penile arteries from obese Zucker rats

    PubMed Central

    Sánchez, A; Contreras, C; Villalba, N; Martínez, P; Martínez, AC; Bríones, A; Salaíces, M; García-Sacristán, A; Hernández, M; Prieto, D

    2010-01-01

    Background and purpose: The aim of the current study was to investigate the role of arachidonic acid (AA) metabolism via cyclooxygenase (COX) in the endothelial dysfunction of penile arteries from pre-diabetic, obese Zucker rats (OZR). Experimental approach: Penile arteries from OZR and from lean Zucker rats (LZR) were mounted in microvascular myographs to assess vascular function and COX expression was determined by immunohistochemistry. Key results: Acetylcholine (ACh) and AA elicited relaxations that were impaired in arteries from OZR. Inhibition of both COX-1 and COX-2 reduced the relaxant effects of ACh and AA in LZR but not in OZR. Inhibitors of COX-1 and of the TXA2/PGH2 (TP) receptor enhanced the relaxations induced by AA in both LZR and OZR, whereas COX-2 inhibition enhanced these responses only in OZR. TP receptor blockade did not restore ACh relaxant responses in arteries from OZR. Inhibition of COX-1 increased basal tension in OZR and this contraction was blunted by TP receptor blockade. The vasoconstrictor responses to noradrenaline were augmented by indomethacin and by COX-2 inhibition in LZR but not in OZR. Immunohistochemical staining showed that both COX-1 and COX-2 are expressed in the endothelium of penile arteries from both LZR and OZR. Conclusions and implications: Vasoactive prostanoids were formed via constitutively active COX-1 and COX-2 pathways in normal rat penile arteries. Under conditions of insulin resistance, the release and/or effects of vasodilator prostanoids were impaired, contributing to the blunted endothelium-dependent vasodilatation and to the enhanced vasoconstriction. PMID:20082610

  20. The exploration of thienothiazines as selective butyrylcholinesterase inhibitors.

    PubMed

    Karlsson, Daniela; Fallarero, Adyary; Brunhofer, Gerda; Mayer, Claudia; Prakash, Ohm; Mohan, C Gopi; Vuorela, Pia; Erker, Thomas

    2012-08-30

    The role of butyrylcholinesterase (BChE) in the progression of Alzheimer's disease (AD) has recently become more crucial. In the AD brain, selective BChE inhibitors have been demonstrated to have a beneficial effect in vivo, probably by recovering cholinergic activity and/or by restoring AChE:BChE activity ratios to the levels observed in the healthy brain. Thienothiazines are compounds sharing some structural features with phenothiazines, which are known to be potent BChE inhibitors. Thus, in this contribution 45 thienothiazines were investigated for their BChE inhibitory activity. Six of them were proven to be potent and selective inhibitors of equine BChE's hydrolase activity. Structure-activity relationships were laid out, and a tentative pharmacophore model for BChE inhibitors of the thienothiazine type was proposed. The most active compound, 3f, displayed a mixed type of inhibition and was also active against the human BChE (huBChE) with an IC(50) huBChE of 0.51 ± 0.07 μM. Computational studies suggested that 3f likely binds to the catalytic site and nearby to the peripheral site of the huBChE in an extended form. In addition, the chemical space occupied by the active thienothiazines, as opposed to phenothiazines and other representative chemical classes of BChE inhibitors, was explored with the aid of ChemGPS-NP, and the relevant chemical space regions were identified. This study shows for the first time that thienothiazines represent a new group of BChE inhibitors that can be used as molecular probes for studying the role of BChE in the brain or for developing newer drug leads for AD therapy.

  1. Treatment of diabetic rats with a peroxynitrite decomposition catalyst prevents induction of renal COX-2.

    PubMed

    Chen, Yu-Jung; Santos, Margarita; Quilley, John

    2011-03-01

    Cyclooxygenase (COX)-2 expression is increased in the kidney of rats made diabetic with streptozotocin and associated with enhanced release of prostaglandins stimulated by arachidonic acid (AA). Treatment of diabetic rats with nitro-L-arginine methyl ester (L-NAME) to inhibit nitric oxide synthase or with tempol to reduce superoxide prevented these changes, suggesting the possibility that peroxynitrite (ONOO) may be the stimulus for the induction of renal COX-2 in diabetes. Consequently, we tested the effects of an ONOO decomposition catalyst, 5,10,15,20-tetrakis(N-methyl-4'-pyridyl)porphyrinato iron(III) (FeTMPyP), which was administered for 3-4 wk after the induction of diabetes. FeTMPyP treatment normalized the twofold increase in the expression of nitrotyrosine, a marker for ONOO formation, in the diabetic rat and prevented the increase in renal COX-2 expression without modifying the two- to threefold increases in renal release of prostaglandins PGE(2) and 6-ketoPGF(1α) in response to AA. FeTMPyP treatment of diabetic rats reduced the elevated creatinine clearance and urinary excretion of TNF-α and transforming growth factor (TGF)-β, suggesting a renoprotective effect. Double immunostaining of renal sections and immunoprecipitation of COX-2 and nitrotyrosine suggested nitration of COX-2 in diabetic rats. In cultured human umbilical vein endothelial cells (HUVECs) exposed to elevated glucose (450 mg/dl) or ONOO derived from 3-morpholinosydnonimine (SIN-1), expression of COX-2 was increased and was prevented when endothelial cells were treated with FeTMPyP. These results indicate that elevated glucose increases the formation of ONOO, which contributes to the induction of renal COX-2 in the diabetic rat.

  2. Clinical significance of Cox-2, Survivin and Bcl-2 expression in hepatocellular carcinoma (HCC).

    PubMed

    Yang, Yu; Zhu, Jiang; Gou, Hongfeng; Cao, Dan; Jiang, Ming; Hou, Mei

    2011-09-01

    Cox-2, Survivin and Bcl-2 are frequently overexpressed in numerous types of cancers. They are known to be the important regulators of apoptosis. This study was designed to investigate the correlation between the clinical characteristics and the expression of Cox-2, Survivin and Bcl-2 in hepatocellular carcinoma. A total of 63 postoperative hepatocellular carcinoma (HCC) samples, 10 adjacent non-tumor samples and 10 normal liver samples were immunochemically detected for the expression of Cox-2, Survivin and Bcl-2. A median follow-up of 4 years for the 63 HCC patients was conducted. Univariate tests and multivariate Cox regression were performed for statistical analysis. The Kaplan-Meier method was used to analyze the survival. Positive expression of Cox-2 (84.3%) and Survivin (77.8%) was detected significantly more frequently in the HCC samples than in the normal liver tissues (30% and 0, respectively). Bcl-2 was highly expressed in the adjacent non-tumor tissue. Cox-2 was positively correlative to Survivin. Survivin and Bcl-2 were significantly associated with the pathological grade of HCC (P<0.05). Expression of both Cox-2 and Survivin was significantly associated with the poor overall survival (OS) (P=0.0141, P=0.0039). Furthermore, multivariate analysis confirmed the independent prognostic value of Survivin expression, along with tumor size and hepatic function. Cox-2 and Survivin were highly expressed in the HCC tissue. Survivin and Bcl-2 were significantly associated with the pathological grade of HCC. The expression of Survivin was an independent prognostic factor for HCC after a hepatectomy. Treatment that inhibits Survivin may be a promising targeted approach in HCC.

  3. Convergent synthesis and evaluation of (18)F-labeled azulenic COX2 probes for cancer imaging.

    PubMed

    Nolting, Donald D; Nickels, Michael; Tantawy, Mohammed N; Yu, James Y H; Xie, Jingping; Peterson, Todd E; Crews, Brenda C; Marnett, Larry; Gore, John C; Pham, Wellington

    2012-01-01

    The overall objectives of this research are to (i) develop azulene-based positron emission tomography (PET) probes and (ii) image COX2 as a potential biomarker of breast cancer. Several lines of research have demonstrated that COX2 is overexpressed in breast cancer and that its presence correlates with poor prognoses. While other studies have reported that COX2 inhibition can be modulated and used beneficially as a chemopreventive strategy in cancer, no viable mechanism for achieving that approach has yet been developed. This shortfall could be circumvented through in vivo imaging of COX2 activity, particularly using sensitive imaging techniques such as PET. Toward that goal, our laboratory focuses on the development of novel (18)F-labled COX2 probes. We began the synthesis of the probes by transforming tropolone into a lactone, which was subjected to an [8 + 2] cycloaddition reaction to yield 2-methylazulene as the core ring of the probe. After exploring numerous synthetic routes, the final target molecule and precursor PET compounds were prepared successfully using convergent synthesis. Conventional (18)F labeling methods caused precursor decomposition, which prompted us to hypothesize that the acidic protons of the methylene moiety between the azulene and thiazole rings were readily abstracted by a strong base such as potassium carbonate. Ultimately, this caused the precursors to disintegrate. This observation was supported after successfully using an (18)F labeling strategy that employed a much milder phosphate buffer. The (18)F-labeled COX2 probe was tested in a breast cancer xenograft mouse model. The data obtained via successive whole-body PET/CT scans indicated probe accumulation and retention in the tumor. Overall, the probe was stable in vivo and no defluorination was observed. A biodistribution study and Western blot analysis corroborate with the imaging data. In conclusion, this novel COX2 PET probe was shown to be a promising agent for cancer imaging

  4. Convergent synthesis and evaluation of 18F-labeled azulenic COX2 probes for cancer imaging

    PubMed Central

    Nolting, Donald D.; Nickels, Michael; Tantawy, Mohammed N.; Yu, James Y. H.; Xie, Jingping; Peterson, Todd E.; Crews, Brenda C.; Marnett, Larry; Gore, John C.; Pham, Wellington

    2013-01-01

    The overall objectives of this research are to (i) develop azulene-based positron emission tomography (PET) probes and (ii) image COX2 as a potential biomarker of breast cancer. Several lines of research have demonstrated that COX2 is overexpressed in breast cancer and that its presence correlates with poor prognoses. While other studies have reported that COX2 inhibition can be modulated and used beneficially as a chemopreventive strategy in cancer, no viable mechanism for achieving that approach has yet been developed. This shortfall could be circumvented through in vivo imaging of COX2 activity, particularly using sensitive imaging techniques such as PET. Toward that goal, our laboratory focuses on the development of novel 18F-labled COX2 probes. We began the synthesis of the probes by transforming tropolone into a lactone, which was subjected to an [8 + 2] cycloaddition reaction to yield 2-methylazulene as the core ring of the probe. After exploring numerous synthetic routes, the final target molecule and precursor PET compounds were prepared successfully using convergent synthesis. Conventional 18F labeling methods caused precursor decomposition, which prompted us to hypothesize that the acidic protons of the methylene moiety between the azulene and thiazole rings were readily abstracted by a strong base such as potassium carbonate. Ultimately, this caused the precursors to disintegrate. This observation was supported after successfully using an 18F labeling strategy that employed a much milder phosphate buffer. The 18F-labeled COX2 probe was tested in a breast cancer xenograft mouse model. The data obtained via successive whole-body PET/CT scans indicated probe accumulation and retention in the tumor. Overall, the probe was stable in vivo and no defluorination was observed. A biodistribution study and Western blot analysis corroborate with the imaging data. In conclusion, this novel COX2 PET probe was shown to be a promising agent for cancer imaging and

  5. Development of Selective Covalent Janus Kinase 3 Inhibitors.

    PubMed

    Tan, Li; Akahane, Koshi; McNally, Randall; Reyskens, Kathleen M S E; Ficarro, Scott B; Liu, Suhu; Herter-Sprie, Grit S; Koyama, Shohei; Pattison, Michael J; Labella, Katherine; Johannessen, Liv; Akbay, Esra A; Wong, Kwok-Kin; Frank, David A; Marto, Jarrod A; Look, Thomas A; Arthur, J Simon C; Eck, Michael J; Gray, Nathanael S

    2015-08-27

    The Janus kinases (JAKs) and their downstream effectors, signal transducer and activator of transcription proteins (STATs), form a critical immune cell signaling circuit, which is of fundamental importance in innate immunity, inflammation, and hematopoiesis, and dysregulation is frequently observed in immune disease and cancer. The high degree of structural conservation of the JAK ATP binding pockets has posed a considerable challenge to medicinal chemists seeking to develop highly selective inhibitors as pharmacological probes and as clinical drugs. Here we report the discovery and optimization of 2,4-substituted pyrimidines as covalent JAK3 inhibitors that exploit a unique cysteine (Cys909) residue in JAK3. Investigation of structure-activity relationship (SAR) utilizing biochemical and transformed Ba/F3 cellular assays resulted in identification of potent and selective inhibitors such as compounds 9 and 45. A 2.9 Å cocrystal structure of JAK3 in complex with 9 confirms the covalent interaction. Compound 9 exhibited decent pharmacokinetic properties and is suitable for use in vivo. These inhibitors provide a set of useful tools to pharmacologically interrogate JAK3-dependent biology.

  6. Selectivity of IMAC columns in trypsin inhibitor purification.

    PubMed

    Yeomans-Reina, H; Ruiz-Manriquez, A; Wong, B R; Mansir, A T

    2001-01-01

    The properties of an adsorbent and the parameters in an adsorption process affect the resolution of chromatographic purifications. This is reflected in the elution profile, which shows the relative affinity of different proteins for a specific adsorbent. In the work presented here, elution profiles for trypsin inhibitor were used to study the effects of the concentration of trypsin inhibitor, ionic strength of the protein solution, slope of the elution gradient, and the regeneration treatment of the chromatography column on the selectivity of the adsorbent Cellufine Chelate-Cu(II)(ida). Cytochrome c was used as a reference protein. Variations in the concentrations of trypsin inhibitor and in the ionic strength of the buffered solution did not have any effects on the elution profile. On the other hand, changes in the slope of the pH gradient used for elution caused shifting of the elution peaks toward lower values of the elution volume, resulting in the best strategy to modify the elution profile of the system. Finally, using a constant slope pH gradient of elution, the variation of the selectivity of the adsorbent for trypsin inhibitor when subjected to cleaning treatments with 0.5 N NaOH was studied. Appropriate cleaning practices used in industry were followed. The adsorbent showed only a slight tendency for resolution loss in the order of 2 x 10(-4) days(-1). The results presented here show a good stability of the adsorbent when compared to other biospecific adsorbents commonly used.

  7. Effect of a cyclooxygenase-2 inhibitor on postexercise muscle protein synthesis in humans

    PubMed Central

    Burd, Nicholas A.; Dickinson, Jared M.; LeMoine, Jennifer K.; Carroll, Chad C.; Sullivan, Bridget E.; Haus, Jacob M.; Jemiolo, Bozena; Trappe, Scott W.; Hughes, Gordon M.; Sanders, Charles E.

    2010-01-01

    Nonselective blockade of the cyclooxygenase (COX) enzymes in skeletal muscle eliminates the normal increase in muscle protein synthesis following resistance exercise. The current study tested the hypothesis that this COX-mediated increase in postexercise muscle protein synthesis is regulated specifically by the COX-2 isoform. Sixteen males (23 ± 1 yr) were randomly assigned to one of two groups that received three doses of either a selective COX-2 inhibitor (celecoxib; 200 mg/dose, 600 mg total) or a placebo in double-blind fashion during the 24 h following a single bout of knee extensor resistance exercise. At rest and 24 h postexercise, skeletal muscle protein fractional synthesis rate (FSR) was measured using a primed constant infusion of [2H5]phenylalanine coupled with muscle biopsies of the vastus lateralis, and measurements were made of mRNA and protein expression of COX-1 and COX-2. Mixed muscle protein FSR in response to exercise (P < 0.05) was not suppressed by the COX-2 inhibitor (0.056 ± 0.004 to 0.108 ± 0.014%/h) compared with placebo (0.074 ± 0.004 to 0.091 ± 0.005%/h), nor was there any difference (P > 0.05) between the placebo and COX-2 inhibitor postexercise when controlling for resting FSR. The COX-2 inhibitor did not influence COX-1 mRNA, COX-1 protein, or COX-2 protein levels, whereas it did increase (P < 0.05) COX-2 mRNA (3.0 ± 0.9-fold) compared with placebo (1.3 ± 0.3-fold). It appears that the elimination of the postexercise muscle protein synthesis response by nonselective COX inhibitors is not solely due to COX-2 isoform blockade. Furthermore, the current data suggest that the COX-1 enzyme is likely the main isoform responsible for the COX-mediated increase in muscle protein synthesis following resistance exercise in humans. PMID:19934404

  8. Synthesis of a selective HDAC6 inhibitor active in neuroblasts.

    PubMed

    Zwick, Vincent; Simões-Pires, Claudia A; Nurisso, Alessandra; Petit, Charlotte; Dos Santos Passos, Carolina; Randazzo, Giuseppe Marco; Martinet, Nadine; Bertrand, Philippe; Cuendet, Muriel

    2016-10-15

    In recent years, the role of HDAC6 in neurodegeneration has been partially elucidated, which led some authors to propose HDAC6 inhibitors as a therapeutic strategy to treat neurodegenerative diseases. In an effort to develop a selective HDAC6 inhibitor which can cross the blood brain barrier (BBB), a modified hydroxamate derivative (compound 3) was designed and synthetized. This compound was predicted to have potential for BBB penetration based on in silico and in vitro evaluation of passive permeability. When tested for its HDAC inhibitory activity, the IC50 value of compound 3 towards HDAC6 was in the nM range in both enzymatic and cell-based assays. Compound 3 showed a cell-based selectivity profile close to that of tubastatin A in SH-SY5Y human neuroblastoma cells, and a good BBB permeability profile.

  9. Anandamide and decidual remodelling: COX-2 oxidative metabolism as a key regulator.

    PubMed

    Almada, M; Piscitelli, F; Fonseca, B M; Di Marzo, V; Correia-da-Silva, G; Teixeira, N

    2015-11-01

    Recently, endocannabinoids have emerged as signalling mediators in reproduction. It is widely accepted that anandamide (AEA) levels must be tightly regulated, and that a disturbance in AEA levels may impact decidual stability and regression. We have previously characterized the endocannabinoid machinery in rat decidual tissue and reported the pro-apoptotic action of AEA on rat decidual cells. Cyclooxygenase-2 (COX-2) is an inducible enzyme that plays a crucial role in early pregnancy, and is also a key modulator in the crosstalk between endocannabinoids and prostaglandins. On the other hand, AEA-oxidative metabolism by COX-2 is not merely a mean to inactivate its action, but it yields the formation of a new class of mediators, named prostaglandin-ethanolamides, or prostamides. In this study we found that AEA-induced apoptosis in decidual cells involves COX-2 metabolic pathway. AEA induced COX-2 expression through p38 MAPK, resulting in the formation of prostamide E2 (PME2). Our findings also suggest that AEA-induced effect is associated with NF-kB activation. Finally, we describe the involvement of PME2 in the induction of the intrinsic apoptotic pathway in rat decidual cells. Altogether, our findings highlight the role of COX-2 as a gatekeeper in the uterine environment and clarify the impact of the deregulation of AEA levels on the decidual remodelling process.

  10. Clinicopathological and prognostic significance of COX-2 immunohistochemical expression in breast cancer: a meta-analysis

    PubMed Central

    Xu, Feng; Li, Mengxin; Zhang, Chao; Cui, Jianxiu; Liu, Jun; Li, Jie; Jiang, Hongchuan

    2017-01-01

    The prognostic significance of COX-2 in patients with breast cancer remains controversial. The aims of our meta-analysis are to evaluate its association with clinicopathological characteristics and prognostic value in patients with breast cancer. PubMed, EMBASE, Web of Science, the Ovid Database and Grey literature were systematically searched up to May 2016. Twenty-one studies including 6739 patients with breast cancer were analyzed. The meta-analysis indicated that the incidence difference of COX-2 expression was significant when comparing the lymph node positive group to negative group (OR = 1.76, 95% CI [1.30, 2.39]) and the tumor size ≥ 2cm group to the tumor size < 2cm group (OR = 1.71, 95% CI [1.22, 2.39]). None of other clinicopathological parameters such as the ER status, PR status, HER2 status and the vascular invasion status were associated with COX-2 overexpression. The detection of COX-2 was significantly correlated with the disease-free survival (DFS) of patients (HR = 1.58, 95% CI [1.23, 2.03]) and the overall survival (OS) of patients (HR = 1.51, 95% CI [1.31, 1.72]). Our meta-analysis demonstrates that the presence of high levels of COX-2 is associated with poor prognosis for breast cancer patients and predicts bigger tumor size and lymph node metastasis. PMID:27999206

  11. Analysis of the cytochrome c oxidase subunit II (COX2) gene in giant panda, Ailuropoda melanoleuca.

    PubMed

    Ling, S S; Zhu, Y; Lan, D; Li, D S; Pang, H Z; Wang, Y; Li, D Y; Wei, R P; Zhang, H M; Wang, C D; Hu, Y D

    2017-01-23

    The giant panda, Ailuropoda melanoleuca (Ursidae), has a unique bamboo-based diet; however, this low-energy intake has been sufficient to maintain the metabolic processes of this species since the fourth ice age. As mitochondria are the main sites for energy metabolism in animals, the protein-coding genes involved in mitochondrial respiratory chains, particularly cytochrome c oxidase subunit II (COX2), which is the rate-limiting enzyme in electron transfer, could play an important role in giant panda metabolism. Therefore, the present study aimed to isolate, sequence, and analyze the COX2 DNA from individuals kept at the Giant Panda Protection and Research Center, China, and compare these sequences with those of the other Ursidae family members. Multiple sequence alignment showed that the COX2 gene had three point mutations that defined three haplotypes, with 60% of the sequences corresponding to haplotype I. The neutrality tests revealed that the COX2 gene was conserved throughout evolution, and the maximum likelihood phylogenetic analysis, using homologous sequences from other Ursidae species, showed clustering of the COX2 sequences of giant pandas, suggesting that this gene evolved differently in them.

  12. Selective Inhibitors of 17beta-Hydroxysteroid Dehydrogenase

    DTIC Science & Technology

    2003-07-01

    this project is to develop selective inhibitors of human Type I 17 Beta-HSD as "lead compounds" for stmcture-based drug design . The crystal structure...of human Type I 17 Beta-HSD is available to aid in structure-based drug design . The concept that the Rossmann fold may represent a useful drug target is a new concept in drug design .

  13. The Bitter Barricading of Prostaglandin Biosynthesis Pathway: Understanding the Molecular Mechanism of Selective Cyclooxygenase-2 Inhibition by Amarogentin, a Secoiridoid Glycoside from Swertia chirayita

    PubMed Central

    Sundar, Durai; Thorat, Sunil S.

    2014-01-01

    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 possible

  14. Myricetin blocks lipoteichoic acid-induced COX-2 expression in human gingival fibroblasts.

    PubMed

    Gutiérrez-Venegas, Gloria; Luna, Oscar Alonso; Arreguín-Cano, Juan Antonio; Hernández-Bermúdez, Cristina

    2014-03-01

    Periodontitis is an infectious disease caused by microorganisms present in dental bacterial plaque. Lipoteichoic acid (LTA) is a component of the external membrane of Gram-positive bacteria. It causes septic shock. Ingested flavonoids have been reported to directly affect the regulation of cyclooxygenase-2 (COX-2) expression induced by bacterial toxins. In this study, we examined the effects of four flavonoids (luteolin, fisetin, morin and myricetin) on the activation of ERK1/2, p38 and AKT, and on the synthesis of COX-2 in human gingival fibroblasts treated with LTA from Streptococcus sanguinis. We found that luteolin and myricetin blocked AKT and p38 activation and that myricetin blocked LTA-induced COX-2 expression. The results of our study are important for elucidating the mechanism of action of flavonoid regulation of inflammatory responses.

  15. Preconditioning stress prevents cold restraint stress-induced gastric lesions in rats: roles of COX-1, COX-2, and PLA2.

    PubMed

    Tanaka, Akiko; Hatazawa, Ryo; Takahira, Yuka; Izumi, Nahoko; Filaretova, Ludmila; Takeuchi, Koji

    2007-02-01

    We investigated the protective effect of mild stress on gastric lesions induced by cold-restraint stress, especially concerning prostaglandins (PGs)/cyclo-oxygenase (COX) isozymes. Rats were exposed to severe stress (cold-restraint stress at 10 degrees C for 6 hr) or mild stress (cold-restraint stress at 10 degrees C for 30 min and kept at room temperature for 60 min) followed by severe stress. Severe stress induced gastric lesions, with a concomitant decrease in body temperature (BT). The ulcerogenic response was inhibited by atropine but worsened by indomethacin and SC-560 but not rofecoxib, although none of these agents had any effect on the change in BT. Mild stress suppressed the gastric ulceration and the decrease in BT induced by severe stress, and these effects were reversed by both COX-1 and COX-2 inhibitors. The expression of COX-2 in the stomach was up-regulated from 4 hr after severe stress and this response was slightly expedited by mild stress. COX-2 was also expressed in the hypothalamus under normal and stressed conditions. Quinacrine (phospholipase A(2) inhibitor) attenuated the protective effect of mild stress on the ulceration and decrease in BT caused by severe stress. TA-0910 (TRH analogue) at a low dose also prevented the gastric ulceration and the decrease in BT induced by severe stress. These results suggest that mild stress protects against cold-restraint stress-induced gastric ulceration, and the effect is peripherally and centrally mediated by PGs derived from both COX-1 and COX-2 through the activation of phospholipase A(2). TRH may also be involved in the protective effect of mild stress, probably through regulation of the thermogenic system.

  16. Selective indole-based ECE inhibitors: synthesis and pharmacological evaluation.

    PubMed

    Brands, Michael; Ergüden, Jens-Kerim; Hashimoto, Kentaro; Heimbach, Dirk; Krahn, Thomas; Schröder, Christian; Siegel, Stephan; Stasch, Johannes-Peter; Tsujishita, Hideki; Weigand, Stefan; Yoshida, Nagahiro H

    2006-01-01

    Inhibition of the metalloprotease ECE-1 may be beneficial for the treatment of coronary heart disease, cancer, renal failure, and urological disorders. A novel class of indole-based ECE inhibitors was identified by high throughput screening. Optimization of the original screening lead structure 6 led to highly potent inhibitors such as 11, which bears a bisaryl amide moiety linked to the indole C2 position through an amide group. Docking of 11 into a model structure of ECE revealed a unique binding mode in which the Zn center of the enzyme is not directly addressed by the inhibitor, but key interactions are suggested for the central amide group. Testing of the lead compound 6 in hypertensive Dahl S rats resulted in a decrease in blood pressure after an initial period in which the blood pressure remained unchanged, most probably the result of ET-1 already present. Indole derivative 6 also displays a cardio-protective effect in a mouse model of acute myocardial infarction after oral administration. The more potent chloropyridine derivative 9 antagonizes big-ET-1-induced increase in blood pressure in rats at intravenous administration of 3 mg kg-1. All ECE inhibitors of the indole class showed high selectivity for ECE over related metalloproteases such as NEP and ACE. Therefore, these compounds might have further potential as drugs for the treatment of coronary heart diseases.

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

    PubMed

    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.

  18. DFT analysis and spectral characteristics of Celecoxib a potent COX-2 inhibitor

    NASA Astrophysics Data System (ADS)

    Vijayakumar, B.; Kannappan, V.; Sathyanarayanamoorthi, V.

    2016-10-01

    Extensive quantum mechanical studies are carried out on Celecoxib (CXB), a new generation drug to understand the vibrational and electronic spectral characteristics of the molecule. The vibrational frequencies of CXB are computed by HF and B3LYP methods with 6-311++G (d, p) basis set. The theoretical scaled vibrational frequencies have been assigned and they agreed satisfactorily with experimental FT-IR and Raman frequencies. The theoretical maximum wavelength of absorption of CXB are calculated in water and ethanol by TD-DFT method and these values are compared with experimentally determined λmax values. The spectral and Natural bonds orbital (NBO) analysis in conjunction with spectral data established the presence of intra molecular interactions such as mesomeric, hyperconjugative and steric effects in CXB. The electron density at various positions and reactivity descriptors of CXB indicate that the compound functions as a nucleophile and establish that aromatic ring system present in the molecule is the site of drug action. Electronic distribution and HOMO - LUMO energy values of CXB are discussed in terms of intra-molecular interactions. Computed values of Mulliken charges and thermodynamic properties of CXB are reported.

  19. Cyclooxygenase-2 inhibitors: promise or peril?

    PubMed Central

    Mengle-Gaw, Laurel J; Schwartz, Benjamin D

    2002-01-01

    The discovery of two isoforms of the cyclooxygenase enzyme, COX-1 and COX-2, and the development of COX-2-specific inhibitors as anti-inflammatories and analgesics have offered great promise that the therapeutic benefits of NSAIDs could be optimized through inhibition of COX-2, while minimizing their adverse side effect profile associated with inhibition of COX-1. While COX-2 specific inhibitors have proven to be efficacious in a variety of inflammatory conditions, exposure of large numbers of patients to these drugs in postmarketing studies have uncovered potential safety concerns that raise questions about the benefit/risk ratio of COX-2-specific NSAIDs compared to conventional NSAIDs. This article reviews the efficacy and safety profiles of COX-2-specific inhibitors, comparing them with conventional NSDAIDs. PMID:12467519

  20. Non-steroidal anti-inflammatory drugs, Cyclooxygenase-2 inhibitors and paracetamol use in Queensland and in the whole of Australia

    PubMed Central

    Barozzi, Nadia; Tett, Susan E

    2008-01-01

    Background Cross national drug utilization studies can provide information about different influences on physician prescribing. This is important for medicines with issues around safety and quality of use, like non selective non-steroidal anti-inflammatory drugs (ns-NSAIDs) and cyclo-oxygenase-2 (COX-2) inhibitors. To enable comparison of prescription medicine use across different jurisdictions with a range of population sizes, data first need to be compared within Australia to understand whether use in a smaller sub-population may be considered as representative of the total use within Australia. The aim of this study was to compare the utilization of non selective NSAID, COX-2 inhibitors and paracetamol between Queensland and Australia. Method Dispensing data were obtained for concession beneficiaries for Australia for ns-NSAIDs, COX-2 inhibitors and paracetamol subsidized by the PBS over the period 1997–2003. The same data were purchased for Queensland. Data were converted to Defined Daily Dose (DDD)/1000 beneficiaries/day (World Health Organization anatomical therapeutic chemical classification, 2005). Results Total NSAID and paracetamol consumption were similar in Australia and Queensland. Ns-NSAID use decreased sharply with the introduction of COX-2 inhibitors (from approximately 80 to 40 DDD/1000 beneficiaries/day). Paracetamol was constant (approximately 45 DDD/1000 beneficiaries/day). COX-2 inhibitors consumption was initially higher in Queensland than in the whole of Australia. Conclusion Despite initial divergence in celecoxib use between Queensland and Australia, the use of ns-NSAIDs, COX-2 inhibitors and paracetamol overall, in concession beneficiaries, was comparable in Australia and Queensland. PMID:18816393

  1. Arachidonate 12-lipoxygenases with reference to their selective inhibitors

    SciTech Connect

    Yamamoto, Shozo . E-mail: yamamosh@kyoto-wu.ac.jp; Katsukawa, Michiko; Nakano, Ayumi; Hiraki, Emi; Nishimura, Kohji; Jisaka, Mitsuo; Yokota, Kazushige; Ueda, Natsuo

    2005-12-09

    Lipoxygenase is a dioxygenase recognizing a 1-cis,4-cis-pentadiene of polyunsaturated fatty acids. The enzyme oxygenates various carbon atoms of arachidonic acid as a substrate and produces 5-, 8-, 12- or 15-hydroperoxy eicosatetraenoic acid with a conjugated diene chromophore. The enzyme is referred to as 5-, 8-, 12- or 15-lipoxygenase, respectively. Earlier we found two isoforms of 12-lipoxygenase, leukocyte- and platelet-type enzymes, which were distinguished by substrate specificity, catalytic activity, primary structure, gene intron size, and antigenicity. Recently, the epidermis-type enzyme was found as the third isoform. Attempts have been made to find isozyme-specific inhibitors of 12-lipoxygenase, and earlier we found hinokitol, a tropolone, as a potent inhibitor selective for the platelet-type 12-lipoxygenase. More recently, we tested various catechins of tea leaves and found that (-)-geotechnical gallate was a potent and selective inhibitor of human platelet 12-lipoxygenase with an IC{sub 5} of 0.14 {mu}M. The compound was much less active with 12-lipoxygenase of leukocyte-type, 15-, 8-, and 5-lipoxygenases, and cyclo oxygenases-1 and -2.

  2. Identification of an Adamantyl Azaquinolone JNK Selective Inhibitor

    PubMed Central

    2012-01-01

    3-[4-((1S,2S,3R,5S,7S)-5-Hydroxyadamantan-2-ylcarbamoyl)benzyl]-4-oxo-1-phenyl-1,4-dihydro-[1,8]naphthyridine-2-carboxylic acid methyl ester (4) was identified as a novel, druglike and selective quinolone pan JNK inhibitor. In this communication, some of the structure–activity relationship of the azaquinolone analogues leading to 4 is discussed. The focus is on how changes at the amide functionality affected the biochemical potency, cellular potency, metabolic properties, and solubility of this class of JNK inhibitors. Optimization of these properties led to the identification of the adamantyl analogue, 4. 4 achieved proof of mechanism in both rat and mouse TNF-α challenge models. PMID:24900545

  3. Cyclopamine and jervine induce COX-2 overexpression in human erythroleukemia cells but only cyclopamine has a pro-apoptotic effect

    SciTech Connect

    Ghezali, Lamia; Leger, David Yannick; Limami, Youness; Cook-Moreau, Jeanne; Beneytout, Jean-Louis; Liagre, Bertrand

    2013-04-15

    Erythroleukemia is generally associated with a very poor response and survival to current available therapeutic agents. Cyclooxygenase-2 (COX-2) has been described to play a crucial role in the proliferation and differentiation of leukemia cells, this enzyme seems to play an important role in chemoresistance in different cancer types. Previously, we demonstrated that diosgenin, a plant steroid, induced apoptosis in HEL cells with concomitant COX-2 overexpression. In this study, we investigated the antiproliferative and apoptotic effects of cyclopamine and jervine, two steroidal alkaloids with similar structures, on HEL and TF1a human erythroleukemia cell lines and, for the first time, their effect on COX-2 expression. Cyclopamine, but not jervine, inhibited cell proliferation and induced apoptosis in these cells. Both compounds induced COX-2 overexpression which was responsible for apoptosis resistance. In jervine-treated cells, COX-2 overexpression was NF-κB dependent. Inhibition of NF-κB reduced COX-2 overexpression and induced apoptosis. In addition, cyclopamine induced apoptosis and COX-2 overexpression via PKC activation. Inhibition of the PKC pathway reduced both apoptosis and COX-2 overexpression in both cell lines. Furthermore, we demonstrated that the p38/COX-2 pathway was involved in resistance to cyclopamine-induced apoptosis since p38 inhibition reduced COX-2 overexpression and increased apoptosis in both cell lines. - Highlights: ► Cyclopamine alone but not jervine induces apoptosis in human erythroleukemia cells. ► Cyclopamine and jervine induce COX-2 overexpression. ► COX-2 overexpression is implicated in resistance to cyclopamine-induced apoptosis. ► Apoptotic potential of jervine is restrained by NF-κB pathway activation. ► PKC is involved in cyclopamine-induced apoptosis and COX-2 overexpression.

  4. Characterisation of (R)-2-(2-Fluorobiphenyl-4-yl)-N-(3-Methylpyridin-2-yl)Propanamide as a Dual Fatty Acid Amide Hydrolase: Cyclooxygenase Inhibitor

    PubMed Central

    Gouveia-Figueira, Sandra; Karlsson, Jessica; Deplano, Alessandro; Hashemian, Sanaz; Svensson, Mona; Fredriksson Sundbom, Marcus; Congiu, Cenzo; Onnis, Valentina; Fowler, Christopher J.

    2015-01-01

    Background Increased endocannabinoid tonus by dual-action fatty acid amide hydrolase (FAAH) and substrate selective cyclooxygenase (COX-2) inhibitors is a promising approach for pain-relief. One such compound with this profile is 2-(2-fluorobiphenyl-4-yl)-N-(3-methylpyridin-2-yl)propanamide (Flu-AM1). These activities are shown by Flu-AM1 racemate, but it is not known whether its two single enantiomers behave differently, as is the case towards COX-2 for the parent flurbiprofen enantiomers. Further, the effects of the compound upon COX-2-derived lipids in intact cells are not known. Methodology/Principal Findings COX inhibition was determined using an oxygraphic method with arachidonic acid and 2-arachidonoylglycerol (2-AG) as substrates. FAAH was assayed in mouse brain homogenates using anandamide (AEA) as substrate. Lipidomic analysis was conducted in unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Both enantiomers inhibited COX-2 in a substrate-selective and time-dependent manner, with IC50 values in the absence of a preincubation phase of: (R)-Flu-AM1, COX-1 (arachidonic acid) 6 μM; COX-2 (arachidonic acid) 20 μM; COX-2 (2-AG) 1 μM; (S)-Flu-AM1, COX-1 (arachidonic acid) 3 μM; COX-2 (arachidonic acid) 10 μM; COX-2 (2-AG) 0.7 μM. The compounds showed no enantiomeric selectivity in their FAAH inhibitory properties. (R)-Flu-AM1 (10 μM) greatly inhibited the production of prostaglandin D2 and E2 in both unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Levels of 2-AG were not affected either by (R)-Flu-AM1 or by 10 μM flurbiprofen, either alone or in combination with the FAAH inhibitor URB597 (1 μM). Conclusions/Significance Both enantiomers of Flu-AM1 are more potent inhibitors of 2-AG compared to arachidonic acid oxygenation by COX-2. Inhibition of COX in lipopolysaccharide + interferon γ- stimulated RAW 264.7 cells is insufficient to affect 2-AG levels despite the

  5. The Selectivity of CK2 Inhibitor Quinalizarin: A Reevaluation

    PubMed Central

    Cozza, Giorgio; Venerando, Andrea; Sarno, Stefania; Pinna, Lorenzo A.

    2015-01-01

    Many polyphenolic compounds have been reported to inhibit protein kinases, with special reference to CK2, a pleiotropic serine/threonine kinase, implicated in neoplasia, neurodegenerative disease, and viral infections. In general however these compounds are not endowed with stringent selectivity. Among them quinalizarin (1,2,5,8-tetrahydroxyanthraquinone) turned out to be particularly potent (Ki = 0.058 μM) and quite selective as judged by profiling it on a small panel of 70 protein kinases. Here, by profiling quinalizarin on a larger panel of 140 kinases we reach the conclusion that quinalizarin is one of the most selective inhibitors of CK2, superior to the first-in-class CK2 inhibitor, CX-4945, now in clinical trials for the treatment of cancer. Moreover here we show that quinalizarin is able to discriminate between the isolated CK2 catalytic subunit (CK2α) and CK2 holoenzyme (CK2α2β2), consistent with in silico and in vitro analyses. PMID:26558278

  6. Development of a selective inhibitor of Protein Arginine Deiminase 2.

    PubMed

    Muth, Aaron; Subramanian, Venkataraman; Beaumont, Edward; Nagar, Mitesh; Kerry, Philip; McEwan, Paul; Srinath, Hema; Clancy, Kathleen Wanda; Parelkar, Sangram S; Thompson, Paul R

    2017-03-22

    Protein arginine deiminase 2 (PAD2) plays a key role in the onset and progression of multiple sclerosis, rheumatoid arthritis and breast cancer. To date, no PAD2-selective inhibitor has been developed. Such a compound will be critical for elucidating the biological roles of this isozyme and may ultimately be useful for treating specific diseases in which PAD2 activity is dysregulated. To achieve this goal, we synthesized a series of benzimidazole-based derivatives of Cl-amidine, hypothesizing that this scaffold would allow access to a series of PAD2-selective inhibitors with enhanced cellular efficacy. Herein, we demonstrate that substitutions at both the N-terminus and C-terminus of Cl-amidine result in >100-fold increases in PAD2 potency and selectivity (30a, 41a, and 49a) as well as cellular efficacy 30a. Notably, these compounds use the far less reactive fluoroacetamidine warhead. In total, we predict that 30a will be a critical tool for understanding cellular PAD2 function and sets the stage for treating diseases in which PAD2 activity is dysregulated.

  7. Metabolically Labile Fumarate Esters Impart Kinetic Selectivity to Irreversible Inhibitors.

    PubMed

    Zaro, Balyn W; Whitby, Landon R; Lum, Kenneth M; Cravatt, Benjamin F

    2016-12-14

    Electrophilic small molecules are an important class of chemical probes and drugs that produce biological effects by irreversibly modifying proteins. Examples of electrophilic drugs include covalent kinase inhibitors that are used to treat cancer and the multiple sclerosis drug dimethyl fumarate. Optimized covalent drugs typically inactivate their protein targets rapidly in cells, but ensuing time-dependent, off-target protein modification can erode selectivity and diminish the utility of reactive small molecules as chemical probes and therapeutics. Here, we describe an approach to confer kinetic selectivity to electrophilic drugs. We show that an analogue of the covalent Bruton's tyrosine kinase (BTK) inhibitor Ibrutinib bearing a fumarate ester electrophile is vulnerable to enzymatic metabolism on a time-scale that preserves rapid and sustained BTK inhibition, while thwarting more slowly accumulating off-target reactivity in cell and animal models. These findings demonstrate that metabolically labile electrophilic groups can endow covalent drugs with kinetic selectivity to enable perturbation of proteins and biochemical pathways with greater precision.

  8. ZN2+ INDUCES COX-2 EXPRESSION THROUGH DOWNREGULATION OF LIPID PHOSPHATASE PTEN

    EPA Science Inventory

    Zn2+ Induces COX-2 Expression through Downregulation of Lipid Phosphatase PTEN
    Weidong Wu*, James M. Samet, Philip A. Bromberg*?, Young E. Whang?, and Lee M. Graves* ?
    *CEMALB, ?Department of Medicine, and ?Department of Pharmacology, UNC-Chapel Hill, NC27599; Human Studie...

  9. Evidence for a novel mitochondrial promoter preceding the cox2 gene of perennial teosintes.

    PubMed Central

    Newton, K J; Winberg, B; Yamato, K; Lupold, S; Stern, D B

    1995-01-01

    We have characterized two promoters of the cytochrome oxidase subunit 2 (cox2) gene in Zea perennis mitochondria present in maize lines. Initiation at a site 907 bases upstream of the start codon results in the major approximately 1900 nt cox2 transcript. A sequence just upstream of this site conforms to the consensus described for maize mitochondrial promoters and its transcription is correctly initiated in a maize mitochondrial in vitro transcription extract. A second transcription initiation site (-347) is used only when the dominant allele of a nuclear gene, Mct, is present and its use results in an additional, shorter major transcript. Sequences flanking the Mct-dependent transcription initiation site, which we have termed the conditional promoter of cox2 (cpc), do not fit the maize mitochondrial promoter consensus and do not function in the maize in vitro transcription extract. The cpc region does not hybridize with mitochondrial, chloroplast or nuclear DNAs from most maize or teosinte lines. However, the cpc sequence is found in the same position upstream of the cox2 gene in Zea diploperennis mtDNA and it has striking similarity to the previously reported 'ORF of unknown origin' fused to the ATPase subunit 6 gene in maize CMS-C mitochondria. cpc appears to represent a new type of mitochondrial promoter. Further analysis of both conditional and constitutive promoters should help us to better understand the control of transcription in plant mitochondria. Images PMID:7859746

  10. Elevated COX2 expression and PGE2 production by downregulation of RXRα in senescent macrophages

    SciTech Connect

    Chen, Huimin; Ma, Feng; Hu, Xiaona; Jin, Ting; Xiong, Chuhui; Teng, Xiaochun

    2013-10-11

    Highlights: •Downregulation of RXRα in senescent macrophage. •RXRα suppresses NF-κB activity and COX2 expression. •Increased PGE2 production due to downregulation of RXRα. -- Abstract: Increased systemic level of inflammatory cytokines leads to numerous age-related diseases. In senescent macrophages, elevated prostaglandin E2 (PGE2) production contributes to the suppression of T cell function with aging, which increases the susceptibility to infections. However, the regulation of these inflammatory cytokines and PGE2 with aging still remains unclear. We have verified that cyclooxygenase (COX)-2 expression and PGE2 production are higher in LPS-stimulated macrophages from old mice than that from young mice. Downregulation of RXRα, a nuclear receptor that can suppress NF-κB activity, mediates the elevation of COX2 expression and PGE2 production in senescent macrophages. We also have found less induction of ABCA1 and ABCG1 by RXRα agonist in senescent macrophages, which partially accounts for high risk of atherosclerosis in aged population. Systemic treatment with RXRα antagonist HX531 in young mice increases COX2, TNF-α, and IL-6 expression in splenocytes. Our study not only has outlined a mechanism of elevated NF-κB activity and PGE2 production in senescent macrophages, but also provides RXRα as a potential therapeutic target for treating the age-related diseases.

  11. Antinociceptive Effects of Prim-O-Glucosylcimifugin in Inflammatory Nociception via Reducing Spinal COX-2.

    PubMed

    Wu, Liu-Qing; Li, Yu; Li, Yuan-Yan; Xu, Shi-Hao; Yang, Zong-Yong; Lin, Zheng; Li, Jun

    2016-07-01

    We measured anti-nociceptive activity of prim-o-glucosylcimifugin (POG), a molecule from Saposhnikovia divaricate (Turcz) Schischk. Anti-nociceptive or anti-inflammatory effects of POG on a formalin-induced tonic nociceptive response and a complete Freund's adjuvant (CFA) inoculation-induced rat arthritis pain model were studied. Single subcutaneous injections of POG produced potent anti-nociception in both models that was comparable to indomethacin analgesia. Anti-nociceptive activity of POG was dose-dependent, maximally reducing pain 56.6% with an ED50 of 1.6 mg. Rats given POG over time did not develop tolerance. POG also time-dependently reduced serum TNFα, IL-1β and IL-6 in arthritic rats and both POG and indomethacin reduced spinal prostaglandin E2 (PGE2). Like indomethacin which inhibits cyclooxygenase-2 (COX-2) activity, POG dose-dependently decreased spinal COX-2 content in arthritic rats. Additionally, POG, and its metabolite cimifugin, downregulated COX-2 expression in vitro. Thus, POG produced potent anti-nociception by downregulating spinal COX-2 expression.

  12. GROWTH FACTORS AND COX2 IN WOUND HEALING: AN EXPERIMENTAL STUDY WITH EHRLICH TUMORS

    PubMed Central

    SALGADO, Flávio L. L.; ARTIGIANI-NETO, Ricardo; LOPES-FILHO, Gaspar de Jesus

    2016-01-01

    ABSTRACT Background: Healing is an innate biological phenomenon, and carcinogenesis acquired, but with common humoral and cellular elements. Carcinogenesis interferes negatively in healing. Aim: To evaluate the histological changes in laparotomy scars of healthy Balb/c mice and with an Ehrlich tumor in its various forms of presentation. Methods: Fifty-four mice were divided into three groups of 18 animals. First group was the control; the second had Ehrlich tumor with ascites; and the third had the subcutaneous form of this tumor. Seven days after tumor inoculation, all 54 mice were submitted to laparotomy. All of the animals in the experiment were operated on again on 7th day after surgery, with resection of the scar and subsequent euthanasia of the animal. The scars were sent for histological assessment using immunohistochemical techniques to evaluate Cox-2 (cyclooxygenase 2), VEGF (vascular endothelial growth factor) and FGF (fibroblast growth factor). Semi-quantitatively analysis was done in the laparotomy scars and in the abdominal walls far away from the site of the operation. Results: Assessing the weight of the animals, the correct inoculation of the tumor and weight gain in the group with tumoral ascites was observed. The histological studies showed that groups with the tumor showed a statistically significant higher presence of Cox-2 compared to the control. In the Cox-2 analysis of the abdominal wall, the ascites group showed the most significant difference. VEGF did not present any significant differences between the three groups, regardless of the site. The FGF showed a significant increase in animals with the tumor. Conclusion: Histological findings in both laparotomy scar and the abdominal wall showed that with Ehrlich's neoplasia there was an exacerbated inflammatory response, translated by more intense expression of Cox-2 and greater fibroblast proliferation, translated by more intense expression of FGF, that is, it stimulated both the immediate

  13. Elevated COX-2 Expression Promotes Angiogenesis Through EGFR/p38-MAPK/Sp1-Dependent Signalling in Pancreatic Cancer.

    PubMed

    Hu, Hai; Han, Ting; Zhuo, Meng; Wu, Lei-Lei; Yuan, Cuncun; Wu, Lixia; Lei, Wang; Jiao, Feng; Wang, Li-Wei

    2017-03-28

    Cyclooxygenase-2 (COX-2) was stated to be overexpression in various human malignancies associating with angiogenesis, metastasis and chemoresistence. Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease displaying many of these characteristics. A common abnormality of PDAC is overexpression of specificity protein-1 (Sp1), which was said to correlate with malignant phenotypes of human cancers. Using RNA-seq data from The Cancer Genome Atlas (TCGA), we found that Sp1 expression was positively correlated with that of COX-2 in PDAC, and that the inhibition or overexpression of Sp1 in PDAC cells leads to decreased or elevated COX-2 expression. Luciferase reporter gene and chromatin immunoprecipitation (ChIP) assays revealed that elevated transcription of COX-2 requires Sp1 binding to sequence positions around -245/-240 of COX-2 promoter. Activated epidermal growth factor receptor (EGFR) and downstream p38 mitogen-activated protein kinase (p38-MAPK) were also profoundly altered in PDAC. The inhibition of EGFR/p38-MAPK signaling resulted in reduced Sp1 activation, decreased COX-2 and vascular endothelial growth factor (VEGF) expression. Thus, Sp1 could transcriptionally activate COX-2 expression in a process relies on activated EGFR/p38-MAPK signaling. Finally, we found that the inhibition of COX-2 leads to decreased angiogenesis in a process dependent on VEGF, which link COX-2 to angiogenesis in PDAC.

  14. The potential role of COX-2 in cancer stem cell-mediated canine mammary tumor initiation: an immunohistochemical study.

    PubMed

    Huang, Jian; Zhang, Di; Xie, Fuqiang; Lin, Degui

    2015-01-01

    Increasing evidence suggests that cancer stem cells (CSCs) are responsible for tumor initiation and maintenance. Additionally, it is becoming apparent that cyclooxygenase (COX) signaling is associated with canine mammary tumor development. The goals of the present study were to investigate COX-2 expression patterns and their effect on CSC-mediated tumor initiation in primary canine mammary tissues and tumorsphere models using immunohistochemistry. Patterns of COX-2, CD44, octamer-binding transcription factor (Oct)-3/4, and epidermal growth factor receptor (EGFR) expression were examined in malignant mammary tumor (MMT) samples and analyzed in terms of clinicopathological characteristics. COX-2 and Oct-3/4 expression was higher in MMTs compared to other histological samples with heterogeneous patterns. In MMTs, COX-2 expression correlated with tumor malignancy features. Significant associations between COX-2, CD44, and EGFR were observed in low-differentiated MMTs. Comparative analysis showed that the levels of COX-2, CD44, and Oct-3/4 expression varied significantly among TSs of three histological grades. Enhanced COX-2 staining was consistently observed in TSs. Similar levels of staining intensity were found for CD44 and Oct-3/4, but EGFR expression was weak. Our findings indicate the potential role of COX-2 in CSC-mediated tumor initiation, and suggest that COX-2 inhibition may help treat canine mammary tumors by targeting CSCs.

  15. N-methyl-citalopram: A quaternary selective serotonin reuptake inhibitor.

    PubMed

    Bismuth-Evenzal, Yona; Roz, Netta; Gurwitz, David; Rehavi, Moshe

    2010-11-15

    We describe the synthesis and the pharmacological characterization of a new quaternary selective serotonin reuptake inhibitor (SSRI) N-methyl-citalopram (NMC) with periphery restricted action due to its inability to cross the blood brain barrier. NMC recognized and blocked the human platelet serotonin transporter (SERT) with similar affinity to that of citalopram as was evident from competition binding studies with [(3)H]citalopram and uptake studies with [(3)H]5-HT. In contrast, the affinity of NMC to rat brain SERT was 10-fold lower than its parent compound citalopram. Similarly to citalopram, NMC did not inhibit dopamine and noradrenaline uptake in rat brain synaptosomes at 10(-7)M as well as [(3)H]ketanserin binding to rat brain membranes at 10(-5)M, demonstrating its SSRI profile. A comparison of radioactivity retained in perfused mice brain following in vivo intraperitoneal injections of tritium-labeled NMC or citalopram showed that unlike citalopram, NMC did not penetrate the brain. Taken together, our observations suggest that N-methyl-citalopram is a selective serotonin reuptake inhibitor that does not penetrate the mouse brain. Epidemiological studies have suggested that chronic use of SSRI drugs may confer a protective effect against myocardial infarction (MI) apparently reflecting reduced platelet aggregation secondary to reduced platelet serotonin levels. N-methyl-citalopram may therefore have a potential as a new anti-platelet drug that does not cross the blood brain barrier and is thus devoid of the adverse CNS effects of SSRI drugs.

  16. Synthesis and evaluation of heteroarylalanine diacids as potent and selective neutral endopeptidase inhibitors.

    PubMed

    Glossop, Melanie S; Bazin, Richard J; Dack, Kevin N; Fox, David N A; MacDonald, Graeme A; Mills, Mark; Owen, Dafydd R; Phillips, Chris; Reeves, Keith A; Ringer, Tracy J; Strang, Ross S; Watson, Christine A L

    2011-06-01

    Heteroarylalanine derivatives 4 were designed as potential inhibitors of neutral endopeptidase (NEP EC 3.4.24.11). Selectivity over other zinc metalloproteinases was explored through occupation of the S2' subsite within NEP. Structural optimisation led to the identification of 5-phenyl oxazole 4f, a potent and selective NEP inhibitor. A crystal structure of the inhibitor bound complex is reported.

  17. Selective Serotonin Reuptake Inhibitor (SSRI) Antidepressants, Prolactin and Breast Cancer.

    PubMed

    Ashbury, Janet E; Lévesque, Linda E; Beck, Patricia A; Aronson, Kristan J

    2012-01-01

    Selective serotonin reuptake inhibitors (SSRIs) are a widely prescribed class of antidepressants. Laboratory and epidemiologic evidence suggests that a prolactin-mediated mechanism secondary to increased serotonin levels at neuronal synapses could lead to a potentially carcinogenic effect of SSRIs. In this population-based case-control study, we evaluated the association between SSRI use and breast cancer risk as a function of their relative degree of inhibition of serotonin reuptake as a proxy for their impact on prolactin levels. Cases were 2,129 women with primary invasive breast cancer diagnosed from 2003 to 2007, and controls were 21,297 women randomly selected from the population registry. Detailed information for each SSRI prescription dispensed was compiled using the Saskatchewan prescription database. Logistic regression was used to evaluate the impact of use of high and lower inhibitors of serotonin reuptake and duration of use, as well as to assess the effect of individual high inhibitors on the risk of breast cancer. Exclusive users of high or lower inhibitors of serotonin reuptake were not at increased risk for breast cancer compared with non-users of SSRIs (OR = 1.01, CI = 0.88-1.17 and OR = 0.91, CI = 0.67-1.25 respectively), regardless of their duration of use or menopausal status. While we cannot rule out the possibility of a clinically important risk increase (OR = 1.83, CI = 0.99-3.40) for long-term users of sertraline (≥24 prescriptions), given the small number of exposed cases (n = 12), the borderline statistical significance, and the wide confidence interval, these results need to be interpreted cautiously. In this large population-based case-control study, we found no conclusive evidence of breast cancer risk associated with the use of SSRIs even after assessing the degree of serotonin reuptake inhibition and duration of use. Our results do not support the serotonin-mediated pathway for the prolactin

  18. Co-expression of COX-2 and 5-LO in primary glioblastoma is associated with poor prognosis.

    PubMed

    Wang, Xingfu; Chen, Yupeng; Zhang, Sheng; Zhang, Lifeng; Liu, Xueyong; Zhang, Li; Li, Xiaoling; Chen, Dayang

    2015-11-01

    Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LO) are important factors in tumorigenesis and malignant progression; however, studies of their roles in glioblastoma have produced conflicting results. To define the frequencies of COX-2 and 5-LO expression and their correlation with clinicopathological features and prognosis, tumor tissues from 76 cases of newly diagnosed primary ordinary glioblastoma were examined for COX-2 and 5-LO expression by immunohistochemistry. The expression levels of COX-2 and 5-LO and the relationships between the co-expression of COX-2/5-LO and patient age and gender, edema index (EI), Karnofsky Performance Scale and overall survival (OS) were analyzed. COX-2 and 5-LO were expressed in 73.7 % (56/76) and 92.1 % (70/76) of the samples, respectively. Among the clinicopathological characteristics, only age (>60 years) exhibited a significant association with the high expression of COX-2. No statistically significant correlations were found in the 5-LO cohort. A significant positive correlation was revealed between the COX-2 and 5-LO scores (r = 0.374; p = 0.001). The elevated co-expression of COX-2 and 5-LO was observed primarily in the patients over the age of 60 years. Patients with a high expression of COX-2 had a significantly shorter OS (p < 0.01), whereas the immunoexpression of 5-LO was not associated with the OS of patients with glioblastoma. Survival analysis indicated that simultaneous high levels of COX-2 and 5-LO expression were significantly correlated with poor OS and, conversely, that a low/low expression pattern of these two proteins was significantly associated with better OS (p < 0.05). Moreover, the Cox multivariable proportional hazard model showed that a high expression of COX-2, high co-expression of COX-2 and 5-LO, and a high Ki-67 index were significant predictors of shorter OS in primary glioblastoma, independent of age, gender, EI, 5-LO expression and p53 status. The hazard ratios for OS were 2.347 (95 % CI 1

  19. Stromal COX-2 signaling activated by deoxycholic acid mediates proliferation and invasiveness of colorectal epithelial cancer cells

    SciTech Connect

    Zhu, Yingting; Zhu, Min; Lance, Peter

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer Human colonic cancer associated fibroblasts are major sources of COX-2 and PGE{sub 2}. Black-Right-Pointing-Pointer The fibroblasts interact with human colonic epithelial cancer cells. Black-Right-Pointing-Pointer Activation of COX-2 signaling in the fibroblasts affects behavior of the epithelia. Black-Right-Pointing-Pointer Protein Kinase C controls the activation of COX-2 signaling. -- Abstract: COX-2 is a major regulator implicated in colonic cancer. However, how COX-2 signaling affects colonic carcinogenesis at cellular level is not clear. In this article, we investigated whether activation of COX-2 signaling by deoxycholic acid (DCA) in primary human normal and cancer associated fibroblasts play a significant role in regulation of proliferation and invasiveness of colonic epithelial cancer cells. Our results demonstrated while COX-2 signaling can be activated by DCA in both normal and cancer associated fibroblasts, the level of activation of COX-2 signaling is significantly greater in cancer associated fibroblasts than that in normal fibroblasts. In addition, we discovered that the proliferative and invasive potential of colonic epithelial cancer cells were much greater when the cells were co-cultured with cancer associated fibroblasts pre-treated with DCA than with normal fibroblasts pre-treated with DCA. Moreover, COX-2 siRNA attenuated the proliferative and invasive effect of both normal and cancer associate fibroblasts pre-treated with DCA on the colonic cancer cells. Further studies indicated that the activation of COX-2 signaling by DCA is through protein kinase C signaling. We speculate that activation of COX-2 signaling especially in cancer associated fibroblasts promotes progression of colonic cancer.

  20. Immunohistochemical COX-2 overexpression correlates with HER-2/neu overexpression in invasive breast carcinomas: a pilot study.

    PubMed

    Çiriş, Ibrahim Metin; Bozkurt, Kemal Kürşat; Başpinar, Sirin; Kapucuoğlu, Fatma Nilgün

    2011-03-15

    Cyclooxygenase-2 (COX-2) is a prostaglandin synthase that catalyzes the synthesis of prostaglandin G2 and H2. It has been shown that COX-2 plays an important role in tumorigenesis of different tumor types and it is thought to take part in breast carcinogenesis. In the present study, we aimed to investigate the relationship of immunohistochemical COX-2 expression with clinicopathological parameters, including HER-2/neu overexpression in invasive breast carcinoma (IBC). Our study population comprised 10 normal breasts, 25 ductal carcinomas in situ (DCIS), and 51 invasive breast carcinomas. Immunohistochemical overexpressions of COX-2 and HER-2/neu were investigated in sections of formalin-fixed, paraffin-embedded blocks by 3 observers. In normal breast, DCIS and IBC, the COX-2 overexpression rate was 0%, 84%, and 58.8%, respectively. In IBC, COX-2 overexpression had a significant relationship with HER-2/neu overexpression (p=0.026) and a high histological grade (p=0.026). COX-2 expression in both DCIS (n=25) and IBC (n=51) was significantly higher than in normal breast tissue (p<0.0001). In addition, the COX-2 expression rate was significantly higher in DCIS than in IBC (p=0.042). Our results indicated that COX-2 overexpression correlates with aggressive phenotypic features, such as HER-2/neu overexpression and high histological grade in IBC. Increased expression of COX-2 in both DCIS and IBC in comparison to normal breast could indicate a role in breast carcinogenesis. COX-2 overexpression may provide a clinically useful biomarker for estimating tumor aggressiveness.

  1. Triptolide inhibits COX-2 expression by regulating mRNA stability in TNF-{alpha}-treated A549 cells

    SciTech Connect

    Sun, Lixin; Zhang, Shuang; Jiang, Zhenzhou; Huang, Xin; Wang, Tao; Huang, Xiao; Li, Han; Zhang, Luyong

    2011-12-09

    Highlights: Black-Right-Pointing-Pointer Triptolide inhibited COX-2 expression and the half-life of COX-2 mRNA is decreased. Black-Right-Pointing-Pointer The HuR protein shuttling from nucleus to cytoplasm is inhibited by triptolide. Black-Right-Pointing-Pointer Triptolide inhibited 3 Prime -UTR fluorescence reporter gene activity. Black-Right-Pointing-Pointer COX-2 mRNA binding to HuR is decreased by triptolide in pull-down experiments. -- Abstract: Cyclooxygenase-2 (COX-2) over-expression is frequently associated with human non-small-cell lung cancer (NSCLC) and involved in tumor proliferation, invasion, angiogenesis and resistance to apoptosis. In the present study, the effects of triptolide on COX-2 expression in A549 cells were investigated and triptolide was found to inhibit TNF-{alpha}-induced COX-2 expression. In our further studies, it was found that triptolide decreased the half-life of COX-2 mRNA dramatically and that it inhibited 3 Prime -untranslated region (3 Prime -UTR) fluorescence reporter gene activity. Meanwhile, triptolide inhibited the HuR shuttling from nucleus to cytoplasm. After triptolide treatment, decreased COX-2 mRNA in pull-down experiments with anti-HuR antibodies was observed, indicating that the decreased cytoplasmic HuR is responsible for the decreased COX-2 mRNA. Taken together, our results provided evidence for the first time that triptolide inhibited COX-2 expression by COX-2 mRNA stability modulation and post-transcriptional regulation. These results provide a novel mechanism of action for triptolide which may be important in the treatment of lung cancer.

  2. Mitochondrial disease genes COA6, COX6B and SCO2 have overlapping roles in COX2 biogenesis

    PubMed Central

    Ghosh, Alok; Pratt, Anthony T.; Soma, Shivatheja; Theriault, Sarah G.; Griffin, Aaron T.; Trivedi, Prachi P.; Gohil, Vishal M.

    2016-01-01

    Biogenesis of cytochrome c oxidase (CcO), the terminal enzyme of the mitochondrial respiratory chain, is a complex process facilitated by several assembly factors. Pathogenic mutations were recently reported in one such assembly factor, COA6, and our previous work linked Coa6 function to mitochondrial copper metabolism and expression of Cox2, a copper-containing subunit of CcO. However, the precise role of Coa6 in Cox2 biogenesis remained unknown. Here we show that yeast Coa6 is an orthologue of human COA6, and like Cox2, is regulated by copper availability, further implicating it in copper delivery to Cox2. In order to place Coa6 in the Cox2 copper delivery pathway, we performed a comprehensive genetic epistasis analysis in the yeast Saccharomyces cerevisiae and found that simultaneous deletion of Coa6 and Sco2, a mitochondrial copper metallochaperone, or Coa6 and Cox12/COX6B, a structural subunit of CcO, completely abrogates Cox2 biogenesis. Unlike Coa6 deficient cells, copper supplementation fails to rescue Cox2 levels of these double mutants. Overexpression of Cox12 or Sco proteins partially rescues the coa6Δ phenotype, suggesting their overlapping but non-redundant roles in copper delivery to Cox2. These genetic data are strongly corroborated by biochemical studies demonstrating physical interactions between Coa6, Cox2, Cox12 and Sco proteins. Furthermore, we show that patient mutations in Coa6 disrupt Coa6–Cox2 interaction, providing the biochemical basis for disease pathogenesis. Taken together, these results place COA6 in the copper delivery pathway to CcO and, surprisingly, link it to a previously unidentified function of CcO subunit Cox12 in Cox2 biogenesis. PMID:26669719

  3. A Selective Phenelzine Analogue Inhibitor of Histone Demethylase LSD1

    PubMed Central

    2015-01-01

    Lysine-specific demethylase 1 (LSD1) is an epigenetic enzyme that oxidatively cleaves methyl groups from monomethyl and dimethyl Lys4 of histone H3 (H3K4Me1, H3K4Me2) and can contribute to gene silencing. This study describes the design and synthesis of analogues of a monoamine oxidase antidepressant, phenelzine, and their LSD1 inhibitory properties. A novel phenelzine analogue (bizine) containing a phenyl-butyrylamide appendage was shown to be a potent LSD1 inhibitor in vitro and was selective versus monoamine oxidases A/B and the LSD1 homologue, LSD2. Bizine was found to be effective at modulating bulk histone methylation in cancer cells, and ChIP-seq experiments revealed a statistically significant overlap in the H3K4 methylation pattern of genes affected by bizine and those altered in LSD1–/– cells. Treatment of two cancer cell lines, LNCaP and H460, with bizine conferred a reduction in proliferation rate, and bizine showed additive to synergistic effects on cell growth when used in combination with two out of five HDAC inhibitors tested. Moreover, neurons exposed to oxidative stress were protected by the presence of bizine, suggesting potential applications in neurodegenerative disease. PMID:24707965

  4. A selective phenelzine analogue inhibitor of histone demethylase LSD1.

    PubMed

    Prusevich, Polina; Kalin, Jay H; Ming, Shonoi A; Basso, Manuela; Givens, Jeffrey; Li, Xin; Hu, Jianfei; Taylor, Martin S; Cieniewicz, Anne M; Hsiao, Po-Yuan; Huang, Rong; Roberson, Heather; Adejola, Nkosi; Avery, Lindsay B; Casero, Robert A; Taverna, Sean D; Qian, Jiang; Tackett, Alan J; Ratan, Rajiv R; McDonald, Oliver G; Feinberg, Andrew P; Cole, Philip A

    2014-06-20

    Lysine-specific demethylase 1 (LSD1) is an epigenetic enzyme that oxidatively cleaves methyl groups from monomethyl and dimethyl Lys4 of histone H3 (H3K4Me1, H3K4Me2) and can contribute to gene silencing. This study describes the design and synthesis of analogues of a monoamine oxidase antidepressant, phenelzine, and their LSD1 inhibitory properties. A novel phenelzine analogue (bizine) containing a phenyl-butyrylamide appendage was shown to be a potent LSD1 inhibitor in vitro and was selective versus monoamine oxidases A/B and the LSD1 homologue, LSD2. Bizine was found to be effective at modulating bulk histone methylation in cancer cells, and ChIP-seq experiments revealed a statistically significant overlap in the H3K4 methylation pattern of genes affected by bizine and those altered in LSD1-/- cells. Treatment of two cancer cell lines, LNCaP and H460, with bizine conferred a reduction in proliferation rate, and bizine showed additive to synergistic effects on cell growth when used in combination with two out of five HDAC inhibitors tested. Moreover, neurons exposed to oxidative stress were protected by the presence of bizine, suggesting potential applications in neurodegenerative disease.

  5. Quinazoline derivatives as selective CYP1B1 inhibitors.

    PubMed

    Mohd Siddique, Mohd Usman; McCann, Glen J P; Sonawane, Vinay R; Horley, Neill; Gatchie, Linda; Joshi, Prashant; Bharate, Sandip B; Jayaprakash, Venkatesan; Sinha, Barij N; Chaudhuri, Bhabatosh

    2017-04-21

    CYP1B1 is implicated to have a role in the development of breast, ovarian, renal, skin and lung carcinomas. It has been suggested that identification of potent and specific CYP1B1 inhibitors can lead to a novel treatment of cancer. Flavonoids have a compact rigid skeleton which fit precisely within the binding cavity of CYP1B1. Systematic isosteric replacement of flavonoid 'O' atom with 'N' atom led to the prediction that a 'quinazoline' scaffold could be the basis for designing potential CYP1B1 inhibitors. A total of 20 quinazoline analogs were synthesized and screened for CYP1B1 and CYP1A1 inhibition in Sacchrosomes™. IC50 determinations of six compounds with capability of inhibiting CYP1B1 identified quinazolines 5c and 5h as the best candidates for CYP1B1 inhibition, with IC50 values in the nM range. Further selectivity studies with homologous CYPs, belonging to the CYP1, CYP2 and CYP3 family of enzymes, showed that the compounds are likely to be free from critical drug-drug interaction liability. Molecular modelling studies were performed to rationalize the observed enzymatic inhibitions. Further biological studies in live yeast and human cells, harboring CYP1A1 and CYP1B1 enzymes, have illustrated the most potent compounds' cellular permeability and capability of potently inhibiting CYP1B1 enzyme expressed within live cells.

  6. Role of COX-2/mPGES-1/Prostaglandin E2 Cascade in Kidney Injury

    PubMed Central

    Jia, Zhanjun; Zhang, Yue; Ding, Guixia; Heiney, Kristina Marie; Huang, Songming; Zhang, Aihua

    2015-01-01

    COX-2/mPGES-1/PGE2 cascade plays critical roles in modulating many physiological and pathological actions in different organs. In the kidney, this cascade is of high importance in regulating fluid metabolism, blood pressure, and renal hemodynamics. Under some disease conditions, this cascade displays various actions in response to the different pathological insults. In the present review, the roles of this cascade in the pathogenesis of kidney injuries including diabetic and nondiabetic kidney diseases and acute kidney injuries were introduced and discussed. The new insights from this review not only increase the understanding of the pathological role of the COX-2/mPGES-1/PGE2 pathway in kidney injuries, but also shed new light on the innovation of the strategies for the treatment of kidney diseases. PMID:25729216

  7. Stromal COX-2 signaling activated by deoxycholic acid mediates proliferation and invasiveness of colorectal epithelial cancer cells.

    PubMed

    Zhu, Yingting; Zhu, Min; Lance, Peter

    2012-08-31

    COX-2 is a major regulator implicated in colonic cancer. However, how COX-2 signaling affects colonic carcinogenesis at cellular level is not clear. In this article, we investigated whether activation of COX-2 signaling by deoxycholic acid (DCA) in primary human normal and cancer associated fibroblasts play a significant role in regulation of proliferation and invasiveness of colonic epithelial cancer cells. Our results demonstrated while COX-2 signaling can be activated by DCA in both normal and cancer associated fibroblasts, the level of activation of COX-2 signaling is significantly greater in cancer associated fibroblasts than that in normal fibroblasts. In addition, we discovered that the proliferative and invasive potential of colonic epithelial cancer cells were much greater when the cells were co-cultured with cancer associated fibroblasts pre-treated with DCA than with normal fibroblasts pre-treated with DCA. Moreover, COX-2 siRNA attenuated the proliferative and invasive effect of both normal and cancer associate fibroblasts pre-treated with DCA on the colonic cancer cells. Further studies indicated that the activation of COX-2 signaling by DCA is through protein kinase C signaling. We speculate that activation of COX-2 signaling especially in cancer associated fibroblasts promotes progression of colonic cancer.

  8. COX-2 promotes metastasis in nasopharyngeal carcinoma by mediating interactions between cancer cells and myeloid-derived suppressor cells.

    PubMed

    Li, Ze-Lei; Ye, Shu-Biao; OuYang, Li-Yin; Zhang, Han; Chen, Yu-Shan; He, Jia; Chen, Qiu-Yan; Qian, Chao-Nan; Zhang, Xiao-Shi; Cui, Jun; Zeng, Yi-Xin; Li, Jiang

    2015-11-01

    The expansion of myeloid-derived suppressor cells (MDSCs) is a common feature of cancer, but its biological roles and molecular mechanism remain unclear. Here, we investigated a molecular link between MDSC expansion and tumor cell metastasis in nasopharyngeal carcinoma (NPC). We demonstrated that MDSCs expanded and were positively correlated with the elevated tumor COX-2 expression and serum IL-6 levels in NPC patients. Importantly, COX-2 and MDSCs were poor predictors of patient disease-free survival (DFS). Knocking down tumor COX-2 expression hampered functional TW03-mediated-MDSC cell (T-MDSC) induction with IL-6 blocking. We identified that T-MDSCs promoted NPC cell migration and invasion by triggering the epithelial-mesenchymal transition (EMT) on cell-to-cell contact, and T-MDSCs enhanced tumor experimental lung metastasis in vivo. Interestingly, the contact between T-MDSCs and NPC cells enhanced tumor COX-2 expression, which subsequently activated the β-catenin/TCF4 pathway, resulting in EMT of the cancer cells. Blocking transforming growth factor β (TGFβ) or inducible nitric oxide synthase (iNOS) significantly abolished the T-MDSC-induced upregulation of COX-2 and EMT scores in NPC cells, whereas the administration of TGFβ or L-arginine supplements upregulated COX-2 expression and EMT scores in NPC cells. These findings reveal that COX-2 is a key factor mediating the interaction between MDSCs and tumor cells, suggesting that the inhibition of COX-2 or MDSCs has the potential to suppress NPC metastasis.

  9. Novel Allelic Variants in the Canine Cyclooxgenase-2 (Cox-2) Promoter Are Associated with Renal Dysplasia in Dogs

    PubMed Central

    Whiteley, Mary H.; Bell, Jerold S.; Rothman, Debby A.

    2011-01-01

    Renal dysplasia (RD) in dogs is a complex disease with a highly variable phenotype and mode of inheritance that does not follow a simple Mendelian pattern. Cox-2 (Cyclooxgenase-2) deficient mice have renal abnormalities and a pathology that has striking similarities to RD in dogs suggesting to us that mutations in the Cox-2 gene could be the cause of RD in dogs. Our data supports this hypothesis. Sequencing of the canine Cox-2 gene was done from clinically affected and normal dogs. Although no changes were detected in the Cox-2 coding region, small insertions and deletions of GC boxes just upstream of the ATG translation start site were found. These sequences are putative SP1 transcription factor binding sites that may represent important cis-acting DNA regulatory elements that govern the expression of Cox-2. A pedigree study of a family of Lhasa apsos revealed an important statistical correlation of these mutant alleles with the disease. We examined an additional 22 clinical cases from various breeds. Regardless of the breed or severity of disease, all of these had one or two copies of the Cox-2 allelic variants. We suggest that the unusual inheritance pattern of RD is due to these alleles, either by changing the pattern of expression of Cox-2 or making Cox-2 levels susceptible to influences of other genes or environmental factors that play an unknown but important role in the development of RD in dogs. PMID:21346820

  10. Effect of COX-2 (PGE2) and IL-6 on Prostate Cancer Bone Metastases

    DTIC Science & Technology

    2008-02-02

    as indicated, for 14 days. Alkaline phosphatase (ALP) activity in the lysates was assayed by the hydrolysis of p-nitrophenyl phosphate (Sigma) to p... nitrophenol . Absorbance was determined at 405 nm and compared with a p- nitrophenol (Sigma) standard titration curve. ALP activity was normalized to...i.e., the RANKL/OPG/RANK system.1 COX-2, the highly inducible enzyme that catalyzes the conversion of arachidonic acid to prostaglandins, and PGE2

  11. A selective inhibitor of cell proliferation from normal serum.

    PubMed Central

    Harrington, W N; Godman, G C

    1980-01-01

    A factor in normal serum that selectively and reversibly inhibits proliferation of cells in culture has been enriched 160-fold from calf serum by sequential ammonium sulfate precipitation, gel filtration, and lectin-affinity chromatography. DNA synthesis of normal (but not transformed) rat hepatocytes, human lymphoblast lines, and mitogen-stimulated murine spleen cells is inhibited by greater than 90%, and Vero, murine myeloma, MELC, and a human colon carcinoma cell line to a lesser extent. Growth of other cell lines tested was not affected. Responsive cells are arrested apparently in G1 by this inhibitor, the effect of which is maximal by 24 hr and is spontaneously reversible thereafter unless it is renewed. The active fraction is a protein that migrates with the alpha 2-globulins; it is not a lipoprotein, and it is of high apparent molecular weight. PMID:6928635

  12. Serotonin syndrome: fentanyl and selective serotonin reuptake inhibitor interactions.

    PubMed

    Greenier, Ewa; Lukyanova, Valentina; Reede, Lynn

    2014-10-01

    Serotonin syndrome is a rare but potentially fatal adverse drug reaction associated with increased serotonergic activity in the central nervous system. It is characterized by a triad of symptoms, which include altered mental status, neuromuscular hyperactivity, and autonomic instability or hyperactivity. Due to the potential of rapid onset, it is important for clinicians to recognize the signs and symptoms of serotonin syndrome. Serotonin syndrome symptoms may resemble other conditions. Although this article focuses on serotonin syndrome as a result of an adverse interaction of selective serotonin reuptake inhibitors (SSRI) and fentanyl, it is important for not only anesthesia professionals, but all clinicians--such as those in emergency medicine and critical care--to be aware of this syndrome and its management. This article discusses the clinical manifestations of the serotonin syndrome and highlights reported cases of serotonin syndrome specifically related to an interaction between SSRIs and fentanyl, a commonly used opioid in anesthesia practice.

  13. Selective Visualization of Cyclooxygenase-2 in Inflammation and Cancer by Targeted Fluorescent Imaging Agents†

    PubMed Central

    Uddin, Md. Jashim; Crews, Brenda C.; Blobaum, Anna L.; Kingsley, Philip J.; Gorden, D. Lee; McIntyre, J. Oliver; Matrisian, Lynn M.; Subbaramaiah, Kotha; Dannenberg, Andrew J.; Piston, David W.; Marnett, Lawrence J.

    2010-01-01

    Effective diagnosis of inflammation and cancer by molecular imaging is challenging because of interference from non-selective accumulation of the contrast agents in normal tissues. Here we report a series of novel fluorescence imaging agents that efficiently target cyclooxygenase-2 (COX-2), which is normally absent from cells, but is found at high levels in inflammatory lesions, and in many premalignant and malignant tumors. After either intraperitoneal or intravenous injection, these reagents become highly enriched in inflamed or tumor tissue compared to normal tissue and this accumulation provides sufficient signal for in vivo fluorescence imaging. Further, we show that only the intact parent compound is found in the region of interest. COX-2-specific delivery was unambiguously confirmed using animals bearing targeted deletions of COX-2 and by blocking the COX-2 active site with high affinity inhibitors in both in vitro and in vivo models. Because of their high specificity, contrast, and detectability, these COX-2 beacons are ideal candidates for detection of inflammatory lesions or early-stage COX-2-expressing human cancers, such as those in the esophagus, oropharynx, and colon. PMID:20430759

  14. Exogenous hydrogen sulfide promotes C6 glioma cell growth through activation of the p38 MAPK/ERK1/2-COX-2 pathways.

    PubMed

    Zhen, Yulan; Zhang, Wei; Liu, Chujie; He, Jing; Lu, Yun; Guo, Ruixian; Feng, Jianqiang; Zhang, Ying; Chen, Jingfu

    2015-11-01

    Hydrogen sulfide (H2S) participates in multifarious physiological and pathophysiologic progresses of cancer both in vitro and in vivo. We have previously demonstrated that exogenous H2S promoted liver cancer cells proliferation/anti‑apoptosis/angiogenesis/migration effects via amplifying the activation of NF-κB pathway. However, the effects of H2S on cancer cell proliferation and apoptosis are controversial and remain unclear in C6 glioma cells. The present study investigated the effects of exogenous H2S on cancer cells growth via activating p38 MAPK/ERK1/2-COX-2 pathways in C6 glioma cells. C6 glioma cells were treated with 400 µmol/l NaHS (a donor of H2S) for 24 h. The expression levels of phosphorylated (p)-p38 MAPK, total (t)-p38 MAPK, p-ERK1/2, t-ERK1/2, cyclooxygenase-2 (COX-2) and caspase-3 were measured by western blotting assay. Cell viability was detected by Cell Counting Kit-8 (CCK-8). Apoptotic cells were observed by Hoechst 33258 staining assay. Cell proliferation was directly detected under fully automatic inverted microscope. Exposure of C6 glioma cells to NaHS resulted in cell proliferation, as evidenced by an increase in cell viability. In addition, NaHS treatment reduced apoptosis, as indicated by the decreased apoptotic percentage and the cleaved caspase-3 expression. Importantly, exposure of the cells to NaHS increased the expression levels of p-p38 MAPK, p-ERK1/2 and COX-2. Notably, co-treatment of C6 glioma cells with 400 µmol/l NaHS and AOAA (an inhibitor of CBS) largely suppressed the above NaHS-induced effects. Combined treatment with NaHS and SB203580 (an inhibitor of p38 MAPK) or PD-98059 (an inhibitor of ERK1/2) resulted in the synergistic reduction of COX-2 expression and increase of caspase-3 expression, a decreased number of apoptotic cells, along with decreased cell viability. Combined treatment with NS-398 (an inhibitor of COX-2) and NaHS also resulted in the synergistic increase of caspase-3, a decreased in the

  15. Selective Monoacylglycerol Lipase Inhibitors: Antinociceptive versus Cannabimimetic Effects in Mice

    PubMed Central

    Wilkerson, Jenny L.; Mustafa, Mohammed; Abdullah, Rehab; Niphakis, Micah; Wiley, Jenny L.; Cravatt, Benjamin F.; Lichtman, Aron H.

    2015-01-01

    The endogenous cannabinoid 2-arachidonoylglycerol (2-AG) plays an important role in a variety of physiologic processes, but its rapid breakdown by monoacylglycerol lipase (MAGL) results in short-lived actions. Initial MAGL inhibitors were limited by poor selectivity and low potency. In this study, we tested JZL184 [4-nitrophenyl 4-[bis(2H-1,3-benzodioxol-5-yl)(hydroxy)methyl]piperidine-1-carboxylate] and MJN110 [2,5-dioxopyrrolidin-1-yl 4-(bis(4-chlorophenyl)methyl)piperazine-1-carboxylate], MAGL inhibitors that possess increased selectivity and potency, in mouse behavioral assays of neuropathic pain [chronic constriction injury (CCI) of the sciatic nerve], interoceptive cannabimimetic effects (drug-discrimination paradigm), and locomotor activity in an open field test. MJN110 (1.25 and 2.5 mg/kg) and JZL184 (16 and 40 mg/kg) significantly elevated 2-AG and decreased arachidonic acid but did not affect anandamide in whole brains. Both MAGL inhibitors significantly reduced CCI-induced mechanical allodynia with the following potencies [ED50 (95% confidence limit [CL]) values in mg/kg: MJN110 (0.43 [0.30–0.63]) > JZL184 (17.8 [11.6–27.4])] and also substituted for the potent cannabinoid receptor agonist CP55,940 [2-[(1R,2R,5R)-5-hydroxy-2-(3-hydroxypropyl)cyclohexyl]-5-(2-methyloctan-2-yl)phenol] in the drug-discrimination paradigm [ED50 (95% CL) values in mg/kg: MJN110 (0.84 [0.69–1.02]) > JZL184 (24.9 [14.6–42.5])]; however, these compounds elicited differential effects on locomotor behavior. Similar to cannabinoid 1 (CB1) receptor agonists, JZL184 produced hypomotility, whereas MJN110 increased locomotor behavior and did not produce catalepsy or hypothermia. Although both drugs substituted for CP55,940 in the drug discrimination assay, MJN110 was more potent in reversing allodynia in the CCI model than in producing CP55,940-like effects. Overall, these results suggest that MAGL inhibition may alleviate neuropathic pain, while displaying limited

  16. In situ click chemistry generation of cyclooxygenase-2 inhibitors.

    PubMed

    Bhardwaj, Atul; Kaur, Jatinder; Wuest, Melinda; Wuest, Frank

    2017-12-01

    Cyclooxygenase-2 isozyme is a promising anti-inflammatory drug target, and overexpression of this enzyme is also associated with several cancers and neurodegenerative diseases. The amino-acid sequence and structural similarity between inducible cyclooxygenase-2 and housekeeping cyclooxygenase-1 isoforms present a significant challenge to design selective cyclooxygenase-2 inhibitors. Herein, we describe the use of the cyclooxygenase-2 active site as a reaction vessel for the in situ generation of its own highly specific inhibitors. Multi-component competitive-binding studies confirmed that the cyclooxygenase-2 isozyme can judiciously select most appropriate chemical building blocks from a pool of chemicals to build its own highly potent inhibitor. Herein, with the use of kinetic target-guided synthesis, also termed as in situ click chemistry, we describe the discovery of two highly potent and selective cyclooxygenase-2 isozyme inhibitors. The in vivo anti-inflammatory activity of these two novel small molecules is significantly higher than that of widely used selective cyclooxygenase-2 inhibitors.Traditional inflammation and pain relief drugs target both cyclooxygenase 1 and 2 (COX-1 and COX-2), causing severe side effects. Here, the authors use in situ click chemistry to develop COX-2 specific inhibitors with high in vivo anti-inflammatory activity.

  17. Daidzin: a potent, selective inhibitor of human mitochondrial aldehyde dehydrogenase.

    PubMed

    Keung, W M; Vallee, B L

    1993-02-15

    Human mitochondrial aldehyde dehydrogenase (ALDH-I) is potently, reversibly, and selectively inhibited by an isoflavone isolated from Radix puerariae and identified as daidzin, the 7-glucoside of 4',7-dihydroxyisoflavone. Kinetic analysis with formaldehyde as substrate reveals that daidzin inhibits ALDH-I competitively with respect to formaldehyde with a Ki of 40 nM, and uncompetitively with respect to the coenzyme NAD+. The human cytosolic aldehyde dehydrogenase isozyme (ALDH-II) is nearly 3 orders of magnitude less sensitive to daidzin inhibition. Daidzin does not inhibit human class I, II, or III alcohol dehydrogenases, nor does it have any significant effect on biological systems that are known to be affected by other isoflavones. Among more than 40 structurally related compounds surveyed, 12 inhibit ALDH-I, but only prunetin and 5-hydroxydaidzin (genistin) combine high selectivity and potency, although they are 7- to 15-fold less potent than daidzin. Structure-function relationships have established a basis for the design and synthesis of additional ALDH inhibitors that could both be yet more potent and specific.

  18. Compound Selectivity and Target Residence Time of Kinase Inhibitors Studied with Surface Plasmon Resonance.

    PubMed

    Willemsen-Seegers, Nicole; Uitdehaag, Joost C M; Prinsen, Martine B W; de Vetter, Judith R F; de Man, Jos; Sawa, Masaaki; Kawase, Yusuke; Buijsman, Rogier C; Zaman, Guido J R

    2017-02-17

    Target residence time (τ) has been suggested to be a better predictor of the biological activity of kinase inhibitors than inhibitory potency (IC50) in enzyme assays. Surface plasmon resonance binding assays for 46 human protein and lipid kinases were developed. The association and dissociation constants of 80 kinase inhibitor interactions were determined. τ and equilibrium affinity constants (KD) were calculated to determine kinetic selectivity. Comparison of τ and KD or IC50 values revealed a strikingly different view on the selectivity of several kinase inhibitors, including the multi-kinase inhibitor ponatinib, which was tested on 10 different kinases. In addition, known pan-Aurora inhibitors resided much longer on Aurora B than on Aurora A, despite having comparable affinity for Aurora A and B. Furthermore, the γ/δ-selective PI3K inhibitor duvelisib and the δ-selective drug idelalisib had similar 20-fold selectivity for δ- over γ-isoform but duvelisib resided much longer on both targets.

  19. Inflammation and depression: combined use of selective serotonin reuptake inhibitors and NSAIDs or paracetamol and psychiatric outcomes

    PubMed Central

    Köhler, Ole; Petersen, Liselotte; Mors, Ole; Gasse, Christiane

    2015-01-01

    Background Nonsteroidal anti-inflammatory drugs (NSAIDs) and paracetamol have been shown to yield the potential of adjunctive antidepressant treatment effects to selective serotonin reuptake inhibitors (SSRIs); however, when investigating treatment effects of concomitant use, simultaneous evaluation of potential adverse events is important. The objective was thus to investigate treatment effectiveness and safety aspects of concomitant SSRI use with NSAIDs or paracetamol. Methods Within a 25% random sample of the Danish population, we identified all incident SSRI users between 1997 and 2006 (N = 123,351). Effectiveness and safety measures were compared between periods of SSRI use only and periods of combined SSRI and NSAID or paracetamol use by applying Cox regression. Results Among 123,351 SSRI users (follow-up: 53,697.8 person-years), 21,666 (17.5%) used NSAIDs and 10,232 (8.3%) paracetamol concomitantly. Concomitant NSAID use increased the risk of any psychiatric contact [Hazard rate ratio (95%-confidence interval): 1.22 (1.07; 1.38)] and with depression [1.31 (1.11; 1.55)]. Low-dose acetylsalicylic acid reduced the risk of psychiatric contact in general [0.74 (0.56; 0.98)] and with depression [0.71 (0.50; 1.01)]. Ibuprofen reduced the risk of psychiatric contacts [0.76 (0.60; 0.98)]. Concerning safety, paracetamol was associated with increased mortality [3.18 (2.83; 3.58)], especially cardiovascular [2.51 (1.93; 3.28)]. Diclofenac [1.77 (1.22; 2.55)] and the selective COX-2 inhibitors [1.75 (1.21; 2.53)] increased mortality risks. Conclusions Concomitant use of SSRIs and NSAIDs occurred frequently, and effectiveness and safety outcomes varied across individual NSAIDs. Especially low-dose acetylsalicylic acid may represent an adjunctive antidepressant treatment option. The increased mortality risk of concomitant use of paracetamol needs further investigation. PMID:26357585

  20. Expression of COX-2 in platelet-monocyte interactions occurs via combinatorial regulation involving adhesion and cytokine signaling

    PubMed Central

    Dixon, Dan A.; Tolley, Neal D.; Bemis-Standoli, Kristi; Martinez, Mark L.; Weyrich, Andrew S.; Morrow, Jason D.; Prescott, Stephen M.; Zimmerman, Guy A.

    2006-01-01

    Tight regulation of COX-2 expression is a key feature controlling eicosanoid production in atherosclerosis and other inflammatory syndromes. Adhesive interactions between platelets and monocytes occur in these conditions and deliver specific signals that trigger inflammatory gene expression. Using a cellular model of monocyte signaling induced by activated human platelets, we identified the central posttranscriptional mechanisms that regulate timing and magnitude of COX-2 expression. Tethering of monocytes to platelets and to purified P-selectin, a key adhesion molecule displayed by activated platelets, induces NF-κB activation and COX-2 promoter activity. Nevertheless, COX-2 mRNA is rapidly degraded, leading to aborted protein synthesis. Time-dependent signaling of monocytes induces a second phase of transcript accumulation accompanied by COX-2 enzyme synthesis and eicosanoid production. Here, generation of IL-1β, a proinflammatory cytokine, promoted stabilization of COX-2 mRNA by silencing of the AU-rich mRNA decay element (ARE) in the 3′-untranslated region (3'UTR) of the mRNA. Consistent with observed mRNA stabilization, activated platelets or IL-1β treatment induced cytoplasmic accumulation and enhanced ARE binding of the mRNA stability factor HuR in monocytes. These findings demonstrate that activated platelets induce COX-2 synthesis in monocytes by combinatorial signaling to transcriptional and posttranscriptional checkpoints. These checkpoints may be altered in disease and therefore useful as targets for antiinflammatory intervention. PMID:16998585

  1. Expression of cyclooxygenase-2 (COX-2) and p53 in neighboring invasive and in situ components of breast tumors.

    PubMed

    Serra, Katia Piton; Sarian, Luis Otavio; Rodrigues-Peres, Raquel Mary; Vassallo, José; Soares, Fernando Augusto; Pinto, Glauce Aparecida; da Cunha, Isabela Werneck; Shinzato, Julia Yoriko; Derchain, Sophie F M

    2012-05-01

    The aim of the study was to assess the relationship between the expression of COX-2 and p53, hormone receptors and HER-2 in the in situ (DCIS) and invasive components of ductal carcinomas (IDC) of the same breast. The expression of COX-2, p53, and hormone receptors was assessed in 87 cases of IDC with contiguous areas of DCIS. Results showed that there was no difference in COX-2 expression comparing the in situ and invasive components of the tumors. In the in situ component, there was a statistically borderline increase in p53 expression in tumors that also expressed COX-2. ER-positive specimens were more common in the group of tumors that expressed COX-2 in the invasive component. From this study we conclude that the expression of COX-2 was similar in the in situ and invasive components of the breast carcinomas. COX-2 positivity was marginally related with the expression of p53 in the in situ components, and with the ER expression in the invasive components.

  2. COX-2 gene promoter DNA methylation status in eutopic and ectopic endometrium of Egyptian women with endometriosis.

    PubMed

    Zidan, Haidy E; Rezk, Noha A; Alnemr, Amr Abd Almohsen; Abd El Ghany, Amany M

    2015-11-01

    The pathophysiology of COX-2 expression in endometriosis is a matter of debate. The aim was to investigate the role of DNA methylation of the NF-IL6 site within the promoter of COX-2 gene in the pathogenesis of endometriosis. The endometrial tissues (ectopic and eutopic) were collected from 60 women with endometriosis and 30 women without endometriosis (control group). The methylation status of COX-2 was examined by methylation-specific PCR. Quantitative real-time PCR (RT-PCR) was performed to measure COX-2 mRNA levels in endometrial tissues. We found significantly higher levels of COX-2 in ectopic endometriotic tissue compared with eutopic tissue. Also, we found that the frequencies of methylation status of the NF-IL6 site within the COX-2 promoter in the eutopic and ectopic endometrial tissues of endometriosis groups were significantly decreased in comparison to controls (P=0.002, P=0.000 respectively). Our study demonstrated that DNA hypomethylation of the NF-IL6 site within the promoter of COX-2 gene could be a key mechanism for its elevated expression in the eutopic and ectopic tissues of endometriosis.

  3. High expression levels of COX-2 and P300 are associated with unfavorable survival in laryngeal squamous cell carcinoma.

    PubMed

    Chen, Yan-Feng; Luo, Rong-Zhen; Li, Yong; Cui, Bo-Kang; Song, Ming; Yang, An-Kui; Chen, Wen-Kuan

    2013-03-01

    In order to provide a basis for clinical treatment decisions, we explored whether there was a correlation between the expression of COX-2 and P300 and clinical factors in a group of patients with laryngeal squamous cell carcinoma (LSCC). A retrospective analysis of clinicopathological data was conducted in 80 patients with LSCC who presented between January 1997 and December 1998. An immunohistochemistry tissue microarray was conducted of 80 surgically resected LSCC and 20 adjacent normal tissue specimens. Survival analysis and Kaplan-Meier curves were used to compare the effects of clinicopathological factors on survival. The Cox model was applied for multivariate analysis. The expression level of COX-2/P300 in LSCC tissues and adjacent normal tissues were 47.5/50.0 versus 0.0/15.0 %. The expression of COX-2 and P300 was correlated with higher T category, N category, clinical staging, histological grade and recurrence (P < 0.05). P300 expression was correlated with COX-2 expression (P < 0.05). Univariate survival analysis showed that P300, COX-2, N category, clinical staging and recurrence factors were closely correlated with unfavorable survival (P < 0.05). Multivariate analysis showed that COX-2 expression, histological grade and recurrence were independent prognostic factors for LSCC. High expression levels of COX-2 and P300 indicated poor survival outcomes for patients with LSCC.

  4. Differential effect of DDT, DDE, and DDD on COX-2 expression in the human trophoblast derived HTR-8/SVneo cells.

    PubMed

    Dominguez-Lopez, Pablo; Diaz-Cueto, Laura; Olivares, Aleida; Ulloa-Aguirre, Alfredo; Arechavaleta-Velasco, Fabian

    2012-11-01

    The purpose of this study was to investigate the effect of 1,1,1-trichloro-2,2-bis-(chlorophenyl)ethane (DDT), 1,1-bis-(chlorophenyl)-2,2-dichloroethene (DDE), and 1,1-dichloro-2,2-bis(chlorophenyl)ethane (DDD) isomers on COX-2 expression in a human trophoblast-derived cell line. Cultured HTR-8/SVneo trophoblast cells were exposed to DDT isomers and its metabolites for 24 h, and COX-2 mRNA and protein expression were assessed by RT-PCR, Western blotting, and ELISA. Prostaglandin E₂ production was also measured by ELISA. Both COX-2 mRNA and protein were detected under control (unexposed) conditions in the HTR-8/SVneo cell line. COX-2 protein expression and prostaglandin E₂ production but not COX-2 mRNA levels increased only after DDE and DDD isomers exposure. It is concluded that DDE and DDD exposure induce the expression of COX-2 protein, leading to increased prostaglandin E2 production. Interestingly, the regulation of COX-2 by these organochlorines pesticides appears to be at the translational level.

  5. Identification of potential ACAT-2 selective inhibitors using pharmacophore, SVM and SVR from Chinese herbs.

    PubMed

    Qiao, Lian-Sheng; Zhang, Xian-Bao; Jiang, Lu-di; Zhang, Yan-Ling; Li, Gong-Yu

    2016-11-01

    Acyl-coenzyme A cholesterol acyltransferase (ACAT) plays an important role in maintaining cellular and organismal cholesterol homeostasis. Two types of ACAT isozymes with different functions exist in mammals, named ACAT-1 and ACAT-2. Numerous studies showed that ACAT-2 selective inhibitors are effective for the treatment of hypercholesterolemia and atherosclerosis. However, as a typical endoplasmic reticulum protein, ACAT-2 protein has not been purified and revealed, so combinatorial ligand-based methods might be the optimal strategy for discovering the ACAT-2 selective inhibitors. In this study, selective pharmacophore models of ACAT-1 inhibitors and ACAT-2 inhibitors were built, respectively. The optimal pharmacophore model for each subtype was identified and utilized as queries for the Traditional Chinese Medicine Database screening. A total of 180 potential ACAT-2 selective inhibitors were obtained, which were identified using an ACAT-2 pharmacophore and not by our ACAT-1 model. Selective SVM model and bioactive SVR model were generated for further identification of the obtained ACAT-2 inhibitors. Ten compounds were finally obtained with predicted inhibitory activities toward ACAT-2. Hydrogen bond acceptor, 2D autocorrelations, GETAWAY descriptors, and BCUT descriptors were identified as key structural features for selectivity and activity of ACAT-2 inhibitors. This study provides a reasonable ligand-based approach to discover potential ACAT-2 selective inhibitors from Chinese herbs, which could help in further screening and development of ACAT-2 selective inhibitors.

  6. Cyclooxygenases in human and mouse skin and cultured human keratinocytes: association of COX-2 expression with human keratinocyte differentiation

    NASA Technical Reports Server (NTRS)

    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.

  7. Low plasma renin and reduced renin secretory responses to acute stimuli in conscious COX-2-deficient mice.

    PubMed

    Kim, Soo Mi; Chen, Limeng; Mizel, Diane; Huang, Yuning G; Briggs, Josie P; Schnermann, Jurgen

    2007-01-01

    In the current experiments, we determined the response of plasma renin concentration (PRC) to acute intraperitoneal administration of furosemide (40 mg/kg), hydralazine (2 mg/kg), isoproterenol (10 mg/kg), candesartan (50 microg), or quinaprilate (50 microg) in conscious wild-type (WT) and cyclooxygenase (COX)-2-/- mice on three different genetic backgrounds (mixed, C57BL/6, 129J). PRC was measured in plasma obtained by tail vein puncture. Basal PRC was significantly lower in COX-2-/- than WT mice independent of genetic background (51, 10, and 17% of WT in mixed, 129J, and C57BL/6). All five acute interventions caused significant increases of PRC in both COX-2+/+ and -/- mice, but the response was consistently less in COX-2-deficient mice (e.g., DeltaPRC in ng ANG I x ml(-1) x h(-1) caused by furosemide, isoproterenol, hydralazine, quinaprilate, or candesartan 4,699 +/- 544, 3,534 +/- 957, 2,522 +/- 369, 9,453 +/- 1,705, 66,455 +/- 21,938 in 129J WT, and 201 +/- 78, 869 +/- 275, 140 +/- 71, 902 +/- 304, 2,660 +/- 954 in 129J COX-2-/-). A low-NaCl diet and enalapril for 1 wk caused a 14-fold elevation of PRC in COX-2-/- mice and was associated with a greatly increased PRC response to acute furosemide (DeltaPRC 201 +/- 78 before and 15,984 +/- 2,397 after low Na/enalapril). As measured by radiotelemetry, blood pressure and heart rate responses to furosemide, hydralazine, isoproterenol, candesartan, or quinaprilate were not different between COX-2 genotypes. In conclusion, chronic absence of COX-2 reduces renin expression, release, and PRC and is associated with a reduced ability to alter PRC during acute stimulation regardless of the nature of the stimulus. COX-2 activity does not appear to be a mandatory and specific requirement for furosemide-stimulated renin secretion.

  8. Basal Bone Phenotype and Increased Anabolic Responses to Intermittent Parathyroid Hormone in Healthy Male COX-2 Knockout Mice

    PubMed Central

    Xu, Manshan; Choudhary, Shilpa; Voznesensky, Olga; Gao, Qi; Adams, Douglas; Diaz-Doran, Vilmaris; Wu, Qian; Goltzman, David; Raisz, Lawrence G.; Pilbeam, Carol C.

    2011-01-01

    Cyclooxygenase-2 (COX-2) knockout (KO) mice in inbred strains can have renal dysfunction with secondary hyperparathyroidism (HPTH), making direct effects of COX-2 KO on bone difficult to assess. COX-2 KO mice in an outbred CD-1 background did not have renal dysfunction but still had two-fold elevated PTH compared to wild type (WT) mice. Compared to WT mice, KO mice had increased serum markers of bone turnover, decreased femoral bone mineral density (BMD) and cortical bone thickness, but no differences in trabecular bone volume by μCT or dynamic histomorphometry. Because PTH is a potent inducer of COX-2 and prostaglandin (PG) production, we examined effects of COX-2 KO on bone responses after three weeks of intermittent PTH. Intermittent PTH increased femoral BMD and cortical bone area more in KO mice than in WT mice and increased trabecular bone volume in the distal femur in both WT and KO mice. Although not statistically significant, PTH-stimulated increases in trabecular bone tended to be greater in KO mice than in WT mice. PTH increased serum markers of bone formation and resorption more in KO than in WT mice but increased the ratio of osteoblastic surface to osteoclastic surface only in KO mice. PTH also increased femoral mineral apposition rates and bone formation rates in KO mice more than in WT mice. Acute mRNA responses to PTH of genes that might mediate some anabolic and catabolic effects of PTH tended to be greater in KO than WT mice. We conclude that (1) the basal bone phenotype in male COX-2 KO mice might reflect HPTH, COX-2 deficiency or both, and (2) increased responses to intermittent PTH in COX-2 KO mice, despite the presence of chronic HPTH, suggest that absence of COX-2 increased sensitivity to PTH. It is possible that manipulation of endogenous PGs could have important clinical implications for anabolic therapy with PTH. PMID:20471507

  9. Effect of etoricoxib, a cyclooxygenase-2 selective inhibitor on aberrant crypt formation and apoptosis in 1,2 dimethyl hydrazine induced colon carcinogenesis in rat model.

    PubMed

    Sharma, P; Kaur, J; Sanyal, S N

    2010-01-01

    Etoricoxib, a second generation selective cyclooxygenase-2 (COX-2) inhibitor had been studied for the chemopreventive response at its therapeutic anti-inflammatory dose in 1,2-dimethylhydrazine (DMH) induced colon carcinogenesis in rat model. Eight to ten weeks old male rats of Sprague-Dawley strain were divided into four groups. While group 1 served as control and received the vehicle of the drugs, group 2 and 3 were administered freshly prepared DMH in 1mM EDTA-saline (pH 7.0) (30 mg/kg body wt/week, subcutaneously). Group 3 was also given a daily treatment of etoricoxib (0.6 mg/kg body wt orally) while the group 4 received the same amount of etoricoxib only, prepared in 0.5% carboxymethyl cellulose. Animals were sacrificed at the end of 6 weeks, body weight recorded and the colons were subjected to macroscopic and histopathological studies. The maximum number of raised mucosal lesions called the multiple plaque lesions (MPL) were found in the DMH group which significantly reverted back in the DMH + etoricoxib group, while very few MPLs were recorded in the control and etoricoxib only group. Similarly, the number of aberrant crypt foci (ACF), the point of future carcinogenic growth, was recorded more in the DMH group and significantly less in the DMH + etoricoxib group. The histopathological analysis showed the presence of severe hyperplasia, occasional dysplasia and aggregates of lymphoid cells in the localized regions. Etoricoxib group showed near normal histological features with the crypt architecture and the surrounding stromal tissue remaining intact. To ascertain the molecular mechanism of such anti-carcinogenic features the colonocytes were isolated and studied in primary culture for the evidence of apoptosis by fluorescent staining and genotoxic changes by single cell gel electrophoresis assay (comet assay) which shows that the DMH treated animals produced much less apoptotic nuclei but more comet producing cell, while these features were reverted back

  10. Substrate-selective Inhibition of Cyclooxygeanse-2 by Fenamic Acid Derivatives Is Dependent on Peroxide Tone.

    PubMed

    Orlando, Benjamin J; Malkowski, Michael G

    2016-07-15

    Cyclooxygenase-2 (COX-2) catalyzes the oxygenation of arachidonic acid (AA) and endocannabinoid substrates, placing the enzyme at a unique junction between the eicosanoid and endocannabinoid signaling pathways. COX-2 is a sequence homodimer, but the enzyme displays half-of-site reactivity, such that only one monomer of the dimer is active at a given time. Certain rapid reversible, competitive nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to inhibit COX-2 in a substrate-selective manner, with the binding of inhibitor to a single monomer sufficient to inhibit the oxygenation of endocannabinoids but not arachidonic acid. The underlying mechanism responsible for substrate-selective inhibition has remained elusive. We utilized structural and biophysical methods to evaluate flufenamic acid, meclofenamic acid, mefenamic acid, and tolfenamic acid for their ability to act as substrate-selective inhibitors. Crystal structures of each drug in complex with human COX-2 revealed that the inhibitor binds within the cyclooxygenase channel in an inverted orientation, with the carboxylate group interacting with Tyr-385 and Ser-530 at the top of the channel. Tryptophan fluorescence quenching, continuous-wave electron spin resonance, and UV-visible spectroscopy demonstrate that flufenamic acid, mefenamic acid, and tolfenamic acid are substrate-selective inhibitors that bind rapidly to COX-2, quench tyrosyl radicals, and reduce higher oxidation states of the heme moiety. Substrate-selective inhibition was attenuated by the addition of the lipid peroxide 15-hydroperoxyeicosatertaenoic acid. Collectively, these studies implicate peroxide tone as an important mechanistic component of substrate-selective inhibition by flufenamic acid, mefenamic acid, and tolfenamic acid.

  11. Regulation of COX-2 transcription in a colon cancer cell line by Pontin52/TIP49a

    PubMed Central

    Carlson, Mary L; Wilson, Ellen T; Prescott, Stephen M

    2003-01-01

    Cyclooxygenase-2 (COX-2) is expressed early in colon carcinogenesis and is known to play a crucial role in the progress of the disease. Here we show that the regulation of the expression of this enzyme in a colon cancer cell line, and in patients, is associated with overexpression of the Wnt pathway-associated proteins, Pontin52/TIP49a and LEF-1. Recently shown to be essential for transformation via the c-Myc pathway, Pontin52/TIP49a promotes COX-2 expression in tissue culture and is overexpressed in colon cancer tissue, co-localizing with COX-2 expression in transformed tissue, relative to paired normal tissue. PMID:14675489

  12. Food Polyphenols Fail to Cause a Biologically Relevant Reduction of COX-2 Activity.

    PubMed

    Willenberg, Ina; Meschede, Anna K; Gueler, Faikah; Jang, Mi-Sun; Shushakova, Nelli; Schebb, Nils Helge

    2015-01-01

    Epidemiologic studies show a correlation between the dietary intake of food polyphenols and beneficial health effects. Several in vitro studies indicate that the anti-inflammatory potential of polyphenols is, at least in part, mediated by a modulation of the enzymes of the arachidonic acid cascade, such as the prostaglandin forming cyclooxygenases (COXs). Evidence that this mode of action can be transferred to the situation in vivo is scarce. This study characterized effects of a subset of polyphenols on COX-2 expression and activity in vitro and compared the potency with known drugs. Next, the in vivo relevance of the observed in vitro effects was tested. Enzyme assays and incubations of polyphenols with the cancer cell line HCA-7 and lipopolysaccharide (LPS) stimulated primary monocytes support the hypothesis that polyphenols can effect COX-2 expression and activity in vitro. The effects were most pronounced in the monocyte assay for wogonin, apigenin, resveratrol and genistein with IC50 values of 1.5 μM, 2.6 μM, 2.8 μM and 7.4 μM. However, these values are 100- to 1000-fold higher in comparison to those of the known pharmaceuticals celecoxib, indomethacin and dexamethasone. In an animal model of LPS induced sepsis, pretreatment with polyphenols (i. p. 100 mg/kg bw) did not result in decreased plasma or tissue prostaglandin levels, whereas the positive control celecoxib effectively attenuated LPS induced prostaglandin formation. These data suggest that despite the moderate potency in vitro, an effect of polyphenols on COX-2 during acute inflammation is unlikely, even if a high dose of polyphenols is ingested.

  13. Candidate genes for antidepressant response to selective serotonin reuptake inhibitors

    PubMed Central

    Lotrich, Francis E; Pollock, Bruce G

    2005-01-01

    Selective serotonin reuptake inhibitors (SSRIs) can safely and successfully treat major depression, although a substantial number of patients benefit only partially or not at all from treatment. Genetic polymorphisms may play a major role in determining the response to SSRI treatment. Nonetheless, it is likely that efficacy is determined by multiple genes, with individual genetic polymorphisms having a limited effect size. Initial studies have identified the promoter polymorphism in the gene coding for the serotonin reuptake transporter as moderating efficacy for several SSRIs. The goal of this review is to suggest additional plausible polymorphisms that may be involved in antidepressant efficacy. These include genes affecting intracellular transductional cascades; neuronal growth factors; stress-related hormones, such as corticotropin-releasing hormone and glucocorticoid receptors; ion channels and synaptic efficacy; and adaptations of monoaminergic pathways. Association analyses to examine these candidate genes may facilitate identification of patients for targeted alternative therapies. Determining which genes are involved may also assist in identifying future, novel treatments. PMID:18568127

  14. Selective serotonin reuptake inhibitors and cardiovascular events: A systematic review

    PubMed Central

    Nezafati, Mohammad Hassan; Eshraghi, Ali; Vojdanparast, Mohammad; Abtahi, Saeed; Nezafati, Pouya

    2016-01-01

    Background: Given the importance of the role of depression in predicting the outcome of cardiovascular disorders, current medications for treating depression, particularly selective serotonin reuptake inhibitors (SSRIs), are taken into consideration. This study aimed to systematically review the published findings in the use of SSRIs and the risk for cardiac events. Materials and Methods: An independent review of the Web of Science, PubMed, Scopus, Cochrane, CINAHL, index Copernicus, and Google Scholar, up to 2014, was performed. We identified studies evaluating the effect of SSRIs, on cardiovascular events. Articles in English with full text availability, review articles, and experimental studies were included in the study. Among 150 studies reviewed based on the included keywords, 17 met the study criteria and were finally reviewed. Results: The use of some types of SSRIs may prevent platelet adhesion and aggregation; control the cardiovascular risk profile including hypertension, insulin resistance, and body weight; and also inhibit inflammatory processes. The appearance of adverse cardiac events, including cardiac arrhythmias (torsade de pointes and QT prolongation), syncope, increased systolic and diastolic right ventricular volume, and the production of pro-inflammatory cytokines leading atherosclerosis development, has also been expected with the chronic use of some types of SSRIs. Conclusion: According to our systematic review, both beneficial and adverse cardiovascular events can be established following the chronic use of various types of SSRIs. Therefore, when taking SSRIs, the cardiovascular effect of each SSRI has to be carefully considered, based on patients’ cardiovascular risk profiles. PMID:27904611

  15. Selective serotonin reuptake inhibitor drug interactions in patients receiving statins.

    PubMed

    Andrade, Chittaranjan

    2014-02-01

    Elderly patients commonly receive statin drugs for the primary or secondary prevention of cardiovascular and cerebrovascular events. Elderly patients also commonly receive antidepressant drugs, usually selective serotonin reuptake inhibitors (SSRIs), for the treatment of depression, anxiety, or other conditions. SSRIs are associated with many pharmacokinetic drug interactions related to the inhibition of the cytochrome P450 (CYP) metabolic pathways. There is concern that drugs that inhibit statin metabolism can trigger statin adverse effects, especially myopathy (which can be potentially serious, if rhabdomyolysis occurs). However, a detailed literature review of statin metabolism and of SSRI effects on CYP enzymes suggests that escitalopram, citalopram, and paroxetine are almost certain to be safe with all statins, and rosuvastatin, pitavastatin, and pravastatin are almost certain to be safe with all SSRIs. Even though other SSRI-statin combinations may theoretically be associated with risks, the magnitude of the pharmacokinetic interaction is likely to be below the threshold for clinical significance. Risk, if at all, lies in combining fluvoxamine with atorvastatin, simvastatin, or lovastatin, and even this risk can be minimized by using lower statin doses and monitoring the patient.

  16. Design of highly potent urea-based, exosite-binding inhibitors selective for glutamate carboxypeptidase II.

    PubMed

    Tykvart, Jan; Schimer, Jiří; Jančařík, Andrej; Bařinková, Jitka; Navrátil, Václav; Starková, Jana; Šrámková, Karolína; Konvalinka, Jan; Majer, Pavel; Šácha, Pavel

    2015-05-28

    We present here a structure-aided design of inhibitors targeting the active site as well as exosites of glutamate carboxypeptidase II (GCPII), a prostate cancer marker, preparing potent and selective inhibitors that are more than 1000-fold more active toward GCPII than its closest human homologue, glutamate carboxypeptidase III (GCPIII). Additionally, we demonstrate that the prepared inhibitor conjugate can be used for sensitive and selective imaging of GCPII in mammalian cells.

  17. COX2/mPGES1/PGE2 pathway regulates PD-L1 expression in tumor-associated macrophages and myeloid-derived suppressor cells.

    PubMed

    Prima, Victor; Kaliberova, Lyudmila N; Kaliberov, Sergey; Curiel, David T; Kusmartsev, Sergei

    2017-01-31

    In recent years, it has been established that programmed cell death protein ligand 1 (PD-L1)-mediated inhibition of activated PD-1(+) T lymphocytes plays a major role in tumor escape from immune system during cancer progression. Lately, the anti-PD-L1 and -PD-1 immune therapies have become an important tool for treatment of advanced human cancers, including bladder cancer. However, the underlying mechanisms of PD-L1 expression in cancer are not fully understood. We found that coculture of murine bone marrow cells with bladder tumor cells promoted strong expression of PD-L1 in bone marrow-derived myeloid cells. Tumor-induced expression of PD-L1 was limited to F4/80(+) macrophages and Ly-6C(+) myeloid-derived suppressor cells. These PD-L1-expressing cells were immunosuppressive and were capable of eliminating CD8 T cells in vitro. Tumor-infiltrating PD-L1(+) cells isolated from tumor-bearing mice also exerted morphology of tumor-associated macrophages and expressed high levels of prostaglandin E2 (PGE2)-forming enzymes microsomal PGE2 synthase 1 (mPGES1) and COX2. Inhibition of PGE2 formation, using pharmacologic mPGES1 and COX2 inhibitors or genetic overexpression of PGE2-degrading enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH), resulted in reduced PD-L1 expression. Together, our study demonstrates that the COX2/mPGES1/PGE2 pathway involved in the regulation of PD-L1 expression in tumor-infiltrating myeloid cells and, therefore, reprogramming of PGE2 metabolism in tumor microenvironment provides an opportunity to reduce immune suppression in tumor host.

  18. Finasteride Enhances the Generation of Human Myeloid-Derived Suppressor Cells by Up-Regulating the COX2/PGE2 Pathway

    PubMed Central

    Liu, Yufeng; Lin, Yingtong; Zhang, Xu; Zhou, Jie; Zhang, Hui; Pan, Ting; Fu, Yongshui

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) have been known to be a key factor in the regulation of the immune system under numerous conditions such as tumors, infections, autoimmune diseases, and transplantations. In contrast to the proposed deleterious role of MDSCs in tumors and infections, MDSCs with their suppressive function are now proved to have the beneficial potential of suppressing the autoimmune response and promoting tolerance to transplantation. Therefore, the expansion of MDSCs could be a promising therapeutic strategy for many diseases. In this study, we aimed to identify FDA-approved drugs that could aid in the expansion of functional MDSCs. We performed a high-throughput screening (HTS) of FDA-approved drugs based on the in vitro human MDSC-differentiation system and identified finasteride (FIN) to have the best potency to aid the generation of human MDSCs. The FIN-induced MDSCs were quite similar to monocytic MDSCs with regard to their surface phenotype, morphology, immunosuppressive function, and related gene expression. Next, we aimed to determine the mechanism of action of FIN and found that FIN induced the expansion of MDSCs through up-regulation of the COX2/PGE2 pathway by enhancing the activity of COX2 promoter. In addition, the administration of indomethacin (IND), a COX2 inhibitor, abrogated the effect of FIN. Based on these results, we suggested that FIN could find applications in the future in the expansion of MDSCs. Further development of FIN-like compounds could be a novel strategy for generating functional MDSCs for immunosuppressive therapies in various immune disorder conditions. PMID:27253400

  19. hCG-induced Sprouty2 mediates amphiregulin-stimulated COX-2/PGE2 up-regulation in human granulosa cells: a potential mechanism for the OHSS

    PubMed Central

    Cheng, Jung-Chien; Fang, Lanlan; Chang, Hsun-Ming; Sun, Ying-Pu; Leung, Peter C. K.

    2016-01-01

    Sprouty2 (SPRY2) is an important intracellular regulator for epidermal growth factor receptor (EGFR)-mediated ERK1/2 signaling. In human granulosa cells, although SPRY2 is expressed, its regulation and function remains complete unknown and must be defined. Our previous study has shown that human chorionic gonadotropin (hCG)/luteinizing hormone (LH) up-regulates the expression levels of EGF-like growth factor, amphiregulin (AREG), which subsequently contributes to the hCG/LH-induced COX-2 expression and PGE2 production. The aim of the present study was to investigate the effect of hCG on SPRY2 expression and the role of hCG-induced SPRY2 in AREG-stimulated COX-2 expression and PGE2 production in human granulosa cells. Our results demonstrated that the expression of SPRY2 was up-regulated by hCG treatment. Using pharmacological inhibitors and siRNA knockdown, we showed that activation of ERK1/2 signaling was required for hCG-induced up-regulation of SPRY2 expression. Further, SPRY2 knockdown attenuated the AREG-induced COX-2 expression and PGE2 production by inhibiting AREG-activated ERK1/2 signaling. Interestingly, we showed that SPRY2 expression levels were significantly increased in granulosa cells of ovarian hyperstimulation syndrome (OHSS) patients. These results for the first time elucidate the physiological roles of SPRY2 in human granulosa cells and suggest that aberrant expression of SPRY2 may contribute to the pathogenesis of OHSS. PMID:27539669

  20. Selective serotonin reuptake inhibitors for premature ejaculation: review of erectile and ejaculatory side effects.

    PubMed

    Lasker, George F; Halis, Fikret; Gokce, Ahmet

    2014-01-01

    Premature ejaculation is one of the most prevalent sexual disorders affecting men today. The lack of approved therapies has resulted in the prescription of many 'off-label' treatments to manage the condition. Selective serotonin reuptake inhibitors have an interesting side effect of prolonging ejaculatory latency. Consequently, these agents are often considered a first line treatment for patients suffering from premature ejaculation. Erectile dysfunction is another common side effect reported by men treated with selective serotonin reuptake inhibitors. Nitric oxide is the primary mediator of erectile function. Preclinical studies have provided evidence that selective serotonin reuptake inhibitors decrease nitric oxide bioavailability. This invited mini-review aims to examine the physiology of the erectile and ejaculatory responses, discuss the indicated and 'off-label' clinical utility of selective serotonin reuptake inhibitors, and to summarize evidence from basic science and clinical studies pertaining to mechanisms of how selective serotonin reuptake inhibitor therapy modifies ejaculatory and erectile function.

  1. A Role for the Inflammatory Mediators Cox-2 and Metalloproteinases in Cancer Stemness.

    PubMed

    Chimal-Ramírez, G K; Espinoza-Sánchez, N A; Fuentes-Pananá, E M

    2015-01-01

    In solid tumors, neoplastic cells are surrounded by a specific microenvironment that integrates the extracellular matrix, lymphatic and blood vessels, and mesenchymal and immune cells, which together are known as the tumor microenvironment (TME). The TME governs many of the aggressive features of tumors, such as local invasion and metastasis. Additionally, new evidence indicates that the TME can trigger stem cell-like programs in cancer cells, forming cancer stem cells (CSC). Experimental and clinical studies suggest that CSCs are resistant to current common cancer therapies and are responsible for tumor recurrence. In this review, we will describe the TME by focusing on how matrix metalloproteinases (MMPs) and cyclooxygenase-2 (COX-2) induce stemness and sustain stem cell maintenance. This reprogramming toward a CSC phenotype may be critical in tumor cell responses to chemotherapy and relapse with more aggressive tumor clones. Therefore, therapeutic agents targeting MMPs and COX-2 in the tumor microenvironment may become important drugs to control the establishment of CSCs and in the overall prognosis of the disease.

  2. Structural characterization of the GSK-3beta active site using selective and non-selective ATP-mimetic inhibitors.

    PubMed

    Bertrand, J A; Thieffine, S; Vulpetti, A; Cristiani, C; Valsasina, B; Knapp, S; Kalisz, H M; Flocco, M

    2003-10-17

    GSK-3beta is a regulatory serine/threonine kinase with a plethora of cellular targets. Consequently, selective small molecule inhibitors of GSK-3beta may have a variety of therapeutic uses including the treatment of neurodegenerative diseases, type II diabetes and cancer. In order to characterize the active site of GSK-3beta, we determined crystal structures of unphosphorylated GSK-3beta in complex with selective and non-selective ATP-mimetic inhibitors. Analysis of the inhibitors' interactions with GSK-3beta in the structures reveals how the enzyme can accommodate a number of diverse molecular scaffolds. In addition, a conserved water molecule near Thr138 is identified that can serve a functional role in inhibitor binding. Finally, a comparison of the interactions made by selective and non-selective inhibitors highlights residues on the edge of the ATP binding-site that can be used to obtain inhibitor selectivity. Information gained from these structures provides a promising route for the design of second-generation GSK-3beta inhibitors.

  3. The role of anti-LeY antibody in the downregulation of MAPKs/COX-2 pathway in gastric cancer.

    PubMed

    Aziz, Faisal; Qiu, Yan

    2014-04-01

    Monoclonal antibody-based treatments of cancer which serve as magic 'bullets' have been established as one of the most successful therapeutic strategies. A variety of antigens has been investigated as targets for the mAb therapy of gastric cancer, including the carbohydrate type 2 blood group antigen. Lewis Y (LeY) is overexpressed on tumor cells surface either as glycoproteins or glycolipids. LeY is difucosylated oligosaccharide with the chemical structure [Fucα1,2Galβ1→4(Fucα1,3)GlcNAcβ1→R], which is catalyzed by fucosyltransferases, such as FUT1 (α1,2) and FUT4 (α1,3). The role of LeY antigen in cancer treatment and prevention has been extensively studied. Moreover, the cyclooxygenase- 2 (COX-2) is an early event protein, highly expressed in H. pylori-related gastric cancer. COX-2 may play a pivotal part in the maintenance of tumor viability, growth, and metastasis. The COX-2 is upregulated in a variety of cancers, including gastric cancer. However, its inhibition may prevent or reverse gastric carcinogenesis. H. pylori mediated alteration of COX-2 through MAPKs pathway is one of the mechanisms that is implicated in gastric cancer. We have found COX-2 and LeY to be correlative sources of specific gastric biomarkers in gastric cancer, which is upregulated in the gastric cancer through MAPKs pathway. In addition, the anti-LeY antibody significantly downregulated the COX-2 expression through MAPKs pathway, helpful to the treatment of gastric cancer. In this review, we summarize the therapeutic effect of anti-LeY antibody, including the crucial role of COX-2 and LeY antigen in gastric cancer and discuss the COX-2 inhibition by anti-LeY antibody through MAPKs pathway.

  4. Towards a universal barcode of oomycetes--a comparison of the cox1 and cox2 loci.

    PubMed

    Choi, Young-Joon; Beakes, Gordon; Glockling, Sally; Kruse, Julia; Nam, Bora; Nigrelli, Lisa; Ploch, Sebastian; Shin, Hyeon-Dong; Shivas, Roger G; Telle, Sabine; Voglmayr, Hermann; Thines, Marco

    2015-11-01

    Oomycetes are a diverse group of eukaryotes in terrestrial, limnic and marine habitats worldwide and include several devastating plant pathogens, for example Phytophthora infestans (potato late blight). The cytochrome c oxidase subunit 2 gene (cox2) has been widely used for identification, taxonomy and phylogeny of various oomycete groups. However, recently the cox1 gene was proposed as a DNA barcode marker instead, together with ITS rDNA. The cox1 locus has been used in some studies of Pythium and Phytophthora, but has rarely been used for other oomycetes, as amplification success of cox1 varies with different lineages and sample ages. To determine which out of cox1 or cox2 is best suited as a universal oomycete barcode, we compared these two genes in terms of (i) PCR efficiency for 31 representative genera, as well as for historic herbarium specimens, and (ii) sequence polymorphism, intra- and interspecific divergence. The primer sets for cox2 successfully amplified all oomycete genera tested, while cox1 failed to amplify three genera. In addition, cox2 exhibited higher PCR efficiency for historic herbarium specimens, providing easier access to barcoding-type material. Sequence data for several historic type specimens exist for cox2, but there are none for cox1. In addition, cox2 yielded higher species identification success, with higher interspecific and lower intraspecific divergences than cox1. Therefore, cox2 is suggested as a partner DNA barcode along with ITS rDNA instead of cox1. The cox2-1 spacer could be a useful marker below species level. Improved protocols and universal primers are presented for all genes to facilitate future barcoding efforts.

  5. Enhanced Responsiveness to Selective Serotonin Reuptake Inhibitors during Lactation

    PubMed Central

    Jury, Nicholas J.; McCormick, Betsy A.; Horseman, Nelson D.; Benoit, Stephen C.; Gregerson, Karen A.

    2015-01-01

    The physiology of mood regulation in the postpartum is poorly understood despite the fact that postpartum depression (PPD) is a common pathology. Serotonergic mechanisms and their dysfunction are widely presumed to be involved, which has led us to investigate whether lactation induces changes in central or peripheral serotonin (5-HT) systems and related affective behaviors. Brain sections from lactating (day 10 postpartum) and age-matched nulliparous (non-pregnant) C57BL/6J mice were processed for 5-HT immunohistochemistry. The total number of 5-HT immunostained cells and optical density were measured. Lactating mice exhibited lower immunoreactive 5-HT and intensity in the dorsal raphe nucleus when compared with nulliparous controls. Serum 5-HT was quantified from lactating and nulliparous mice using radioimmunoassay. Serum 5-HT concentrations were higher in lactating mice than in nulliparous controls. Affective behavior was assessed in lactating and non-lactating females ten days postpartum, as well as in nulliparous controls using the forced swim test (FST) and marble burying task (MBT). Animals were treated for the preceding five days with a selective serotonin reuptake inhibitor (SSRI, citalopram, 5mg/kg/day) or vehicle. Lactating mice exhibited a lower baseline immobility time during the FST and buried fewer marbles during the MBT as compared to nulliparous controls. Citalopram treatment changed these behaviors in lactating mice with further reductions in immobility during the FST and decreased marble burying. In contrast, the same regimen of citalopram treatment had no effect on these behaviors in either non-lactating postpartum or nulliparous females. Our findings demonstrate changes in both central and peripheral 5-HT systems associated with lactation, independent of pregnancy. They also demonstrate a significant interaction of lactation and responsiveness to SSRI treatment, which has important implications in the treatment of PPD. Although recent evidence

  6. Enhanced responsiveness to selective serotonin reuptake inhibitors during lactation.

    PubMed

    Jury, Nicholas J; McCormick, Betsy A; Horseman, Nelson D; Benoit, Stephen C; Gregerson, Karen A

    2015-01-01

    The physiology of mood regulation in the postpartum is poorly understood despite the fact that postpartum depression (PPD) is a common pathology. Serotonergic mechanisms and their dysfunction are widely presumed to be involved, which has led us to investigate whether lactation induces changes in central or peripheral serotonin (5-HT) systems and related affective behaviors. Brain sections from lactating (day 10 postpartum) and age-matched nulliparous (non-pregnant) C57BL/6J mice were processed for 5-HT immunohistochemistry. The total number of 5-HT immunostained cells and optical density were measured. Lactating mice exhibited lower immunoreactive 5-HT and intensity in the dorsal raphe nucleus when compared with nulliparous controls. Serum 5-HT was quantified from lactating and nulliparous mice using radioimmunoassay. Serum 5-HT concentrations were higher in lactating mice than in nulliparous controls. Affective behavior was assessed in lactating and non-lactating females ten days postpartum, as well as in nulliparous controls using the forced swim test (FST) and marble burying task (MBT). Animals were treated for the preceding five days with a selective serotonin reuptake inhibitor (SSRI, citalopram, 5mg/kg/day) or vehicle. Lactating mice exhibited a lower baseline immobility time during the FST and buried fewer marbles during the MBT as compared to nulliparous controls. Citalopram treatment changed these behaviors in lactating mice with further reductions in immobility during the FST and decreased marble burying. In contrast, the same regimen of citalopram treatment had no effect on these behaviors in either non-lactating postpartum or nulliparous females. Our findings demonstrate changes in both central and peripheral 5-HT systems associated with lactation, independent of pregnancy. They also demonstrate a significant interaction of lactation and responsiveness to SSRI treatment, which has important implications in the treatment of PPD. Although recent evidence

  7. Methanolic extract of adlay seed suppresses COX-2 expression of human lung cancer cells via inhibition of gene transcription.

    PubMed

    Hung, Wen-Chun; Chang, Hui-Chiu

    2003-12-03

    Previous results demonstrated that the methanolic extract of adlay seed exerted an antiproliferative effect on human lung cancer cells in vitro and in vivo and might prevent tobacco carcinogen-induced lung tumorigenesis. In this study, the methanolic extract of adlay seed was tested for its regulation of COX-2 expression of human lung cancer cells. Western blot analysis showed that the methanolic extract of adlay seed inhibited basal and TPA-induced COX-2 expression in a dose-dependent fashion, whereas COX-1 expression was not affected. By using a promoter activity assay, it was found that the methanolic extract inhibited basal and TPA-stimulated COX-2 expression at the transcription level. The effect of the methanolic extract on COX-2 expression in vivo was then investigated. The data demonstrated that treatment of the methanolic extract reduced the PGE(2) level in serum and inhibited COX-2 expression of tumor tissues in nude mice. Taken together, these results suggest that inhibition of COX-2 is one of the mechanisms by which the methanolic extract of adlay seed inhibits cancer growth and prevents lung tumorigenesis.

  8. Plasma Levels of Cyclooxygenase-2 (COX-2) and Visfatin During Different Stages and Different Subtypes of Migraine Headaches

    PubMed Central

    Li, Chao; Zhu, Qiushi; He, Qiu; Wang, Junwei; Wang, Fengzhi; Zhang, Hemin

    2017-01-01

    Background The aim of this study was to determine the plasma levels of cyclooxygenase-2 (COX-2) and visfatin in different stages and different subtypes of migraine headaches compared to a control group to elucidate the pathological mechanisms involved. Material/Methods We recruited a case-control cohort of 182 adult migraine patients and 80 age-matched and gender-matched healthy controls. The migraine patients were divided into two groups: the headache-attack-period group (Group A, n=77) and the headache-free-period group (Group B, n=105). The two groups were further divided into subgroups according to whether they had aura symptoms. Solid phase double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was used to measure the plasma levels of COX-2 and visfatin. Statistical analysis was performed using SPSS 17.0. Results The plasma levels of COX-2 and visfatin in the headache-attack-period group were significantly higher than in the headache-free-period group and the control group; there were no significant differences between the headache-free group and the control group. There were no significant differences in plasma levels of COX-2 and visfatin between the subgroups: headache-attack-period with aura subgroup and the headache-attack-period without aura sub group. Conclusions COX-2 and visfatin participated in the pathogenesis of migraine headaches. The presence of aura had no effect on the serum levels of COX-2 and visfatin. PMID:28044053

  9. Plasma Levels of Cyclooxygenase-2 (COX-2) and Visfatin During Different Stages and Different Subtypes of Migraine Headaches.

    PubMed

    Li, Chao; Zhu, Qiushi; He, Qiu; Wang, Junwei; Wang, Fengzhi; Zhang, Hemin

    2017-01-03

    BACKGROUND The aim of this study was to determine the plasma levels of cyclooxygenase-2 (COX-2) and visfatin in different stages and different subtypes of migraine headaches compared to a control group to elucidate the pathological mechanisms involved. MATERIAL AND METHODS We recruited a case-control cohort of 182 adult migraine patients and 80 age-matched and gender-matched healthy controls. The migraine patients were divided into two groups: the headache-attack-period group (Group A, n=77) and the headache-free-period group (Group B, n=105). The two groups were further divided into subgroups according to whether they had aura symptoms. Solid phase double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was used to measure the plasma levels of COX-2 and visfatin. Statistical analysis was performed using SPSS 17.0. RESULTS The plasma levels of COX-2 and visfatin in the headache-attack-period group were significantly higher than in the headache-free-period group and the control group; there were no significant differences between the headache-free group and the control group. There were no significant differences in plasma levels of COX-2 and visfatin between the subgroups: headache-attack-period with aura subgroup and the headache-attack-period without aura sub group. CONCLUSIONS COX-2 and visfatin participated in the pathogenesis of migraine headaches. The presence of aura had no effect on the serum levels of COX-2 and visfatin.

  10. COX-2 expression correlates with microvessel density in non-melanoma skin cancer from renal transplant recipients and immunocompetent individuals.

    PubMed

    O'Grady, Anthony; O'Kelly, Patrick; Murphy, Gillian M; Leader, Mary; Kay, Elaine

    2004-12-01

    Angiogenesis, the generation of a new vascular network, is regulated in part by inducers of endothelial cell migration and proliferation, such as cyclooxygenase-2 (COX-2). Microvessel density (MVD) measurement is widely used to quantify angiogenesis in tissue sections of tumors, including cutaneous malignancies. The increasing number of successful renal transplantations worldwide is producing a progressive increase in patients at risk for non-melanoma skin cancers, such as squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and Bowen's disease (BD), and at significantly increased risk for metastatic SCC. The aim of this study was to investigate whether there was any difference in angiogenesis between these tumor types in renal transplant recipients (RTRs) and immunocompetent individuals (ICIs) and whether angiogenesis in these tumors was related to COX-2 expression. The study measured angiogenesis and COX-2 expression in BD, SCC, BCC, and normal skin from both RTRs and ICIs. Vessel counts were performed, and COX-2 immunoexpression was assessed semiquantitatively. The MVD counts differed significantly between normal skin and all tumor types. Significant differences in MVD density were found between all SCCs and BCCs. BCCs from RTRs had significantly greater MVD at the invasive front of the tumor than BCCs from ICIs. Increased COX-2 expression correlated with increased MVD in all tumors examined. These findings indicate a difference in vascular profiles between RTRs and ICIs in BCCs and suggest a relationship between COX-2 and angiogenesis that may provide a possible treatment target for skin tumors in these 2 patient populations.

  11. Intracranial haemorrhage and use of selective serotonin reuptake inhibitors

    PubMed Central

    de Abajo, Francisco J; Jick, Hershel; Derby, Laura; Jick, Susan; Schmitz, Stephen

    2000-01-01

    Aims In the past few years an increasing number of bleeding disorders have been reported in association with the use of selective serotonin reuptake inhibitors (SSRIs), including serious cases of intracranial haemorrhage, raising concerns about the safety of this class of drugs. The present study was performed to test the hypothesis of an increased risk of intracranial haemorrhage associated with the use of SSRIs. Methods We carried out a case-control study nested in a cohort of antidepressants users with the UK-based General Practice Research Database (GPRD) as the primary source of information. The study cohort encompassed subjects aged between 18 and 79 years who received a first-time prescription for any antidepressant from January, 1990 to October, 1997. Patients with presenting conditions or treatments that could be associated with an increased risk of intracranial haemorrhage were excluded from the cohort. Patients were followed-up until the occurrence of an idiopathic intracranial haemorrhage. Up to four controls per case, matched on age, sex, calendar time and practice were randomly selected from the study cohort. We estimated adjusted odds ratios and 95% confidence intervals of intracranial haemorrhage with current use of SSRIs and other antidepressants as compared with nonuse using conditional logistic regression. Results We identified 65 cases of idiopathic intracranial haemorrhage and 254 matched controls. Current exposure to SSRIs was ascertained in 7 cases (10.8%) and 24 controls (9.7%) resulting in an adjusted OR (95%CI) of 0.8 (0.3,2.3). The estimate for ‘other antidepressants’ was 0.7 (0.3,1.6). The effect measures were not modified by gender or age. No effect related to dose or treatment duration was detected. The risk estimates did not change according to the location of bleeding (intracerebral or subarachnoid). Conclusions Our results are not compatible with a major increased risk of intracranial haemorrhage among users of SSRIs or other

  12. Structural Biology Insight for the Design of Sub-type Selective Aurora Kinase Inhibitors.

    PubMed

    Sarvagalla, Sailu; Coumar, Mohane Selvaraj

    2015-01-01

    Aurora kinase A, B and C, are key regulators of mitosis and are over expressed in many of the human cancers, making them an ideal drug target for cancer chemotherapy. Currently, over a dozen of Aurora kinase inhibitors are in various phases of clinical development. The majority of the inhibitors (VX-680/MK-0457, PHA-739358, CYC116, SNS-314, AMG 900, AT-9283, SCH- 1473759, ABT-348, PF-03814735, R-763/AS-703569, KW-2449 and TAK-901) are pan-selective (isoform non-selective) and few are Aurora A (MLN8054, MLN8237, VX-689/MK5108 and ENMD 2076) and Aurora B (AZD1152 and GSK1070916) sub-type selective. Despite the intensive research efforts in the past decade, no Aurora kinase inhibitor has reached the market. Recent evidence suggests that the sub-type selective Aurora kinase A inhibitor could possess advantages over pan-selective Aurora inhibitors, by avoiding Aurora B mediated neutropenia. However, sub-type selective Aurora kinase A inhibitor design is very challenging due to the similarity in the active site among the isoforms. Structural biology and computational aspects pertaining to the design of Aurora kinase inhibitors were analyzed and found that a possible means to develop sub-type selective inhibitor is by targeting Aurora A specific residues (Leu215, Thr217 and Arg220) or Aurora B specific residues (Arg159, Glu161 and Lys164), near the solvent exposed region of the protein. Particularly, a useful strategy for the design of sub-type selective Aurora A inhibitor could be by targeting Thr217 residue as in the case of MLN8054. Further preclinical and clinical studies with the sub-type selective Aurora inhibitors could help bring them to the market for the treatment of cancer.

  13. Pyrrole-3-carboxamides as potent and selective JAK2 inhibitors.

    PubMed

    Brasca, Maria Gabriella; Nesi, Marcella; Avanzi, Nilla; Ballinari, Dario; Bandiera, Tiziano; Bertrand, Jay; Bindi, Simona; Canevari, Giulia; Carenzi, Davide; Casero, Daniele; Ceriani, Lucio; Ciomei, Marina; Cirla, Alessandra; Colombo, Maristella; Cribioli, Sabrina; Cristiani, Cinzia; Della Vedova, Franco; Fachin, Gabriele; Fasolini, Marina; Felder, Eduard R; Galvani, Arturo; Isacchi, Antonella; Mirizzi, Danilo; Motto, Ilaria; Panzeri, Achille; Pesenti, Enrico; Vianello, Paola; Gnocchi, Paola; Donati, Daniele

    2014-09-01

    We report herein the discovery, structure guided design, synthesis and biological evaluation of a novel class of JAK2 inhibitors. Optimization of the series led to the identification of the potent and orally bioavailable JAK2 inhibitor 28 (NMS-P953). Compound 28 displayed significant tumour growth inhibition in SET-2 xenograft tumour model, with a mechanism of action confirmed in vivo by typical modulation of known biomarkers, and with a favourable pharmacokinetic and safety profile.

  14. Ester Prodrugs of Ketoprofen: Synthesis, In Vitro Stability, In Vivo Biological Evaluation and In Silico Comparative Docking Studies Against COX-1 and COX-2.

    PubMed

    Ahmed, Musa; Azam, Faizul; Gbaj, Abdul; Zetrini, Abdulmottaleb E; Abodlal, Amna Salem; Rghigh, Abir; Elmahdi, Eman; Hamza, Amel; Salama, Mabruk; Bensaber, Salah M

    2016-01-01

    Prompted by the ineptness of the currently used non-steroidal antiinflammatory drugs (NSAIDs) to control gastric mucosal and renal adverse reactions, several ester prodrugs of ketoprofen were synthesized and characterized by IR, 1H NMR and mass spectral data. Physicochemical properties such as aqueous solubility, octanol-water partition coefficient log P, chemical stability and enzymatic hydrolysis of the synthesized molecules have been studied to assess their potential as prodrugs. The obtained results confirmed that all ester prodrugs are chemically stable, possess increased lipophilicity compared to their parent compounds and converted to the active drugs in vivo. All of the tested ester prodrugs exhibited marked anti-inflammatory activity ranging from 91.8% to 113.3% in comparison with the parent drug, ketoprofen. A mutual prodrug obtained from two antiinflammatory molecules, ketoprofen and salicylic acid has been noted to potentiate the activity making it most active molecule of the series. The ulcerogenic index of the ester prodrugs was significantly lower than the parent drug, ketoprofen. Comparative docking studies against X-ray crystal structures of COX-1 and COX-2 further provided understanding of their interaction with the cyclooxygenases that will facilitate design of better inhibitors (or prodrugs) with sufficient specificity for COX-2 against COX-1. The study offers an innovative strategy for finding a molecule with safer therapeutic profile for longterm treatment of inflammatory diseases.

  15. Novel mutant-selective EGFR kinase inhibitors against EGFR T790M

    SciTech Connect

    Zhou, Wenjun; Ercan, Dalia; Chen, Liang; Yun, Cai-Hong; Li, Danan; Capelletti, Marzia; Cortot, Alexis B.; Chirieac, Lucian; Iacob, Roxana E.; Padera, Robert; Engen, John R.; Wong, Kwok-Kin; Eck, Michael J.; Gray, Nathanael S.; Jänne, Pasi A.

    2010-01-12

    The clinical efficacy of epidermal growth factor receptor (EGFR) kinase inhibitors in EGFR-mutant non-small-cell lung cancer (NSCLC) is limited by the development of drug-resistance mutations, including the gatekeeper T790M mutation. Strategies targeting EGFR T790M with irreversible inhibitors have had limited success and are associated with toxicity due to concurrent inhibition of wild-type EGFR. All current EGFR inhibitors possess a structurally related quinazoline-based core scaffold and were identified as ATP-competitive inhibitors of wild-type EGFR. Here we identify a covalent pyrimidine EGFR inhibitor by screening an irreversible kinase inhibitor library specifically against EGFR T790M. These agents are 30- to 100-fold more potent against EGFR T790M, and up to 100-fold less potent against wild-type EGFR, than quinazoline-based EGFR inhibitors in vitro. They are also effective in murine models of lung cancer driven by EGFR T790M. Co-crystallization studies reveal a structural basis for the increased potency and mutant selectivity of these agents. These mutant-selective irreversible EGFR kinase inhibitors may be clinically more effective and better tolerated than quinazoline-based inhibitors. Our findings demonstrate that functional pharmacological screens against clinically important mutant kinases represent a powerful strategy to identify new classes of mutant-selective kinase inhibitors.

  16. Development of Potent and Selective Inhibitors of Aldo-Keto Reductase 1C3 (type 5 17β-Hydroxysteroid Dehydrogenase) Based on N-Phenyl-Aminobenzoates and Their Structure Activity Relationships

    PubMed Central

    Adeniji, Adegoke O.; Twenter, Barry M.; Byrns, Michael C.; Jin, Yi; Chen, Mo; Winkler, Jeffrey D.; Penning, Trevor M.

    2012-01-01

    Aldo-keto reductase 1C3 (AKR1C3; type 5 17β-hydroxysteroid dehydrogenase) is overexpressed in castrate resistant prostate cancer (CRPC) and is implicated in the intratumoral biosynthesis of testosterone and 5α-dihydrotestosterone. Selective AKR1C3 inhibitors are required since compounds should not inhibit the highly related AKR1C1 and AKR1C2 isoforms which are involved in the inactivation of 5α-dihydrotestosterone. NSAIDs, N-phenylanthranilates in particular are potent but non-selective AKR1C3 inhibitors. Using flufenamic acid, 2-{[3-(trifluoromethyl)phenyl]amino}benzoic acid as lead compound, five classes of structural analogs were synthesized and evaluated for AKR1C3 inhibitory potency and selectivity. Structure activity relationship (SAR) studies revealed that a meta-carboxylic acid group relative to the amine conferred pronounced AKR1C3 selectivity without loss of potency, while electron withdrawing groups on the phenylamino B-ring were optimal for AKR1C3 inhibition. Lead compounds did not inhibit COX-1 or COX-2 but blocked the AKR1C3 mediated production of testosterone in LNCaP-AKR1C3 cells. These compounds offer promising leads towards new therapeutics for CRPC. PMID:22263837

  17. Density functional theory calculations of magnetocrystalline anisotropy energies for (Fe1-xCox)2B

    DOE PAGES

    Daene, Markus; Kim, Soo Kyung; Surh, Michael P.; ...

    2015-06-15

    We present and discuss density functional theory calculations of magnetic properties of the family of ferromagnetic compounds, (Fe1-xCox)2B, focusing specifically on the magnetocrystalline anisotropy energy (MAE). Using periodic supercells of various sizes (up to 96 atoms), it is shown that the general qualitative features of the composition dependence of the MAE is in agreement with experimental findings, while our predicted magnitudes are larger than those of experiment. We find that the use of small supercells (6 and 12-atom) favors larger MAE values relative to a statistical sample of configurations constructed with 96-atom supercells. As a result, the effect of latticemore » relaxations is shown to be small. Calculations of the Curie temperature for this alloy are also presented.« less

  18. Acacia ferruginea inhibits inflammation by regulating inflammatory iNOS and COX-2.

    PubMed

    Sakthivel, Kunnathur Murugesan; Guruvayoorappan, Chandrasekaran

    2016-01-01

    Inflammation is a local defensive reaction of a host to cellular injury or infection. Prolonged inflammation can contribute to pathogenesis of many disorders. Identification of naturally occurring phytoconstituents that can suppress inflammatory mediators can lead to the discovery of anti-inflammatory therapeutics. Acacia ferruginea is used traditionally to treat numerous ailments including hemorrhage, irritable bowel syndrome and leprosy. The present study evaluated the anti-inflammatory activity of A. ferruginea extract against acute (carrageenan) and chronic (formaldehyde) inflammation in Balb/c mice. Pre-treatment with A. ferruginea extract (10 mg/kg BW) for 5 consecutive days via intraperitonial (IP) administration significantly inhibited subsequent induction of paw edema in both models; the effects were comparable to that of the standard drug indomethacin. The results also showed the A. ferruginea extract significantly inhibited nitric oxide (NO) synthesis and iNOS expression (as measured in serum), diminished inflammation in - and neutrophil infiltration to - the paw tissues and led to a reduction in the number of COX-2(+) immunoreative cells (as evidenced by histologic and immunohistochemical analyses) in the paws relative to those in paws of mice that received the irritants only. Further, in vitro studies showed the extract could significantly scavenge free radicals generated as in DPPH and NO radical generating assays. Taken together, the results showed that A. ferruginea extract imparted potent anti-oxidant and -inflammatory effects, in part by maintaining oxidative homeostasis, inhibiting NO synthesis and suppressing iNOS and COX-2 expression and so could potentially be exploited as a potential plant-based medication against inflammatory disorders.

  19. CD4, IL-17, and COX-2 Are Associated With Subclinical Inflammation in Malar Melasma.

    PubMed

    Rodríguez-Arámbula, Adriana; Torres-Álvarez, Bertha; Cortés-García, Diego; Fuentes-Ahumada, Cornelia; Castanedo-Cázares, Juan Pablo

    2015-10-01

    The pathogenesis of melasma, a common, photo-induced hyperpigmentary disorder, is not clearly understood. Significant factors linked to melasma are ultraviolet radiation exposure and genetic predisposition. Histological analysis has demonstrated that melasma is caused by a network of cellular interactions among melanocytes, keratinocytes, mast cells, fibroblasts, and dermal vasculature exhibits, features similar to chronic sun damage. Dermal inflammation caused by ultraviolet radiation might play an important role in the hyperpigmentation and reactivation of melasma lesions through the production of melanogenic cytokines and growth factors. Because the role of inflammation in this disorder is unknown, we used histochemistry, immunohistochemistry, and quantitative real-time polymerase chain reaction to evaluate melasma lesions from healthy female patients (n = 20) with malar melasma. Lesional skin without specific solar exposure or photoprotection measures within the previous 4 weeks was compared with nonlesional skin. The increased lymphocytic infiltrate in lesional skin was mainly composed of CD4 T cells, mast cells, and macrophages. Levels of the cytokine interleukin (IL)-17 and the proinflammatory mediator cyclooxygenase (COX)-2 were significantly elevated in affected skin compared with healthy skin. In addition, the Melasma Activity and Severity Index score, fraction of solar elastosis, and epidermal melanin were positively associated with COX-2 expression. There was no statistically significant difference in IL-1α, IL-1β, R-IL1, IL-6, IL-8, vascular endothelial growth factor, and tumor necrosis factor alpha expression levels. Together, these data indicated that melasma under unchallenged conditions is characterized by chronic inflammatory cells and mediators, which may explain its recurrent nature.

  20. Eupafolin inhibits PGE2 production and COX2 expression in LPS-stimulated human dermal fibroblasts by blocking JNK/AP-1 and Nox2/p47{sup phox} pathway

    SciTech Connect

    Tsai, Ming-Horng; Liang, Chan-Jung; Yen, Feng-Lin; Chiang, Yao-Chang; Lee, Chiang-Wen

    2014-09-01

    Eupafolin, a major active component found in the methanol extracts of Phyla nodiflora, has been used to treat inflammation of skin. We examined its effects on cyclooxygenase-2 (COX-2) expression in LPS-treated human dermal fibroblasts. Lipopolysaccharide (LPS) significantly increased prostaglandin-E2 (PGE2) production associated with increased COX-2 expression in Hs68 cells. This effect was blocked by eupafolin, TLR-4 antibody, antioxidants (APO and NAC), as well as inhibitors, including U0126 (ERK1/2), SB202190 (p38), SP600125 (JNK1/2), and Tanshinone IIA (AP-1). In gene regulation level, qPCR and promoter assays revealed that COX-2 expression was attenuated by eupafolin. In addition, eupafolin also ameliorated LPS-induced p47 phox activation and decreased reactive oxygen species (ROS) generation and NADPH oxidase (Nox) activity. Moreover, pretreatment with eupafolin and APO led to reduced LPS-induced phosphorylation of ERK1/2, JNK, and p38. Further, eupafolin attenuated LPS-induced increase in AP-1 transcription factor binding activity as well as the increase in the phosphorylation of c-Jun and c-Fos. In vivo studies have shown that in dermal fibroblasts of LPS treated mice, eupafolin exerted anti-inflammation effects by decreasing COX-2 protein levels. Our results reveal a novel mechanism for anti-inflammatory and anti-oxidative effects of eupafolin that involved inhibition of LPS-induced ROS generation, suppression of MAPK phosphorylation, diminished DNA binding activity of AP-1 and attenuated COX-2 expression leading to reduced production of prostaglandin E2 (PGE2). Our results demonstrate that eupafolin may be used to treat inflammatory responses associated with dermatologic diseases. - Highlights: • LPS activates the Nox2/p47{sup phox}/JNK/AP-1 and induces COX2 expression in Hs68 cells. • Eupafolin inhibits LPS-induced COX-2 expression via Nox2/p47{sup phox} inhibition. • Eupafolin may be used in the treatment of skin diseases involving inflammation.

  1. Biochemical And Structural Evaluation of Highly Selective 2-Arylbenzoxazole-Based Transthyretin Amyloidogenesis Inhibitors

    SciTech Connect

    Johnson, S.M.; Connelly, S.; Wilson, I.A.; Kelly, J.W.

    2009-05-18

    To develop potent transthyretin (TTR) amyloidogenesis inhibitors that also display high binding selectivity in blood, it proves useful to systematically optimize each of the three substructural elements that comprise a typical inhibitor: the two aryl rings and the linker joining them. In the first study, described herein, structural modifications to one aryl ring were evaluated by screening a library of 2-arylbenzoxazoles bearing thyroid hormone-like aryl substituents on the 2-aryl ring. Several potent and highly selective amyloidogenesis inhibitors were identified that exhibit minimal thyroid hormone nuclear receptor and COX-1 binding. High resolution crystal structures (1.3-1.5 A) of three inhibitors (2f, 4f, and 4d) in complex with TTR were obtained to characterize their binding orientation. Collectively, the results demonstrate that thyroid hormone-like substitution patterns on one aryl ring lead to potent and highly selective TTR amyloidogenesis inhibitors that lack undesirable thyroid hormone receptor or COX-1 binding.

  2. Chemical parsing: Dissecting cell dependencies with a toolkit of selective BCL-2 family inhibitors.

    PubMed

    Leverson, Joel D

    2016-01-01

    The BCL-2/BCL-XL inhibitor navitoclax has shown promise for the treatment of cancer but on-target toxicities have limited its utility. Recently, the generation of selective BCL-2 family inhibitors has enabled a careful dissection of BCL-2 biology, and early work indicates that these molecules have improved therapeutic profiles for the treatment of cancer.

  3. Kinobead and Single-Shot LC-MS Profiling Identifies Selective PKD Inhibitors.

    PubMed

    Golkowski, Martin; Vidadala, Rama Subba Rao; Lombard, Chloe K; Suh, Hyong Won; Maly, Dustin J; Ong, Shao-En

    2017-03-03

    ATP-competitive protein kinase inhibitors are important research tools and therapeutic agents. Because there are >500 human kinases that contain highly conserved active sites, the development of selective inhibitors is extremely challenging. Methods to rapidly and efficiently profile kinase inhibitor targets in cell lysates are urgently needed to discover selective compounds and to elucidate the mechanisms of action for polypharmacological inhibitors. Here, we describe a protocol for microgram-scale chemoproteomic profiling of ATP-competitive kinase inhibitors using kinobeads. We employed a gel-free in situ digestion protocol coupled to nanoflow liquid chromatography-mass spectrometry to profile ∼200 kinases in single analytical runs using as little as 5 μL of kinobeads and 300 μg of protein. With our kinobead reagents, we obtained broad coverage of the kinome, monitoring the relative expression levels of 312 kinases in a diverse panel of 11 cancer cell lines. Further, we profiled a set of pyrrolopyrimidine- and pyrazolopyrimidine-based kinase inhibitors in competition-binding experiments with label-free quantification, leading to the discovery of a novel selective and potent inhibitor of protein kinase D (PKD) 1, 2, and 3. Our protocol is useful for rapid and sensitive profiling of kinase expression levels and ATP-competitive kinase inhibitor selectivity in native proteomes.

  4. Potent and selective inhibitors of Helicobacter pylori glutamate racemase (MurI): pyridodiazepine amines.

    PubMed

    Geng, Bolin; Basarab, Gregory; Comita-Prevoir, Janelle; Gowravaram, Madhusudhan; Hill, Pamela; Kiely, Andrew; Loch, James; MacPherson, Lawrence; Morningstar, Marshall; Mullen, George; Osimboni, Ekundayo; Satz, Alexander; Eyermann, Charles; Lundqvist, Tomas

    2009-02-01

    An SAR study of an HTS screening hit generated a series of pyridodiazepine amines as potent inhibitors of Helicobacter pylori glutamate racemase (MurI) showing highly selective anti-H. pylori activity, marked improved solubility, and reduced plasma protein binding. X-ray co-crystal E-I structures were obtained. These uncompetitive inhibitors bind at the MurI dimer interface.

  5. ERK Signal Suppression and Sensitivity to CH5183284/Debio 1347, a Selective FGFR Inhibitor.

    PubMed

    Nakanishi, Yoshito; Mizuno, Hideaki; Sase, Hitoshi; Fujii, Toshihiko; Sakata, Kiyoaki; Akiyama, Nukinori; Aoki, Yuko; Aoki, Masahiro; Ishii, Nobuya

    2015-12-01

    Drugs that target specific gene alterations have proven beneficial in the treatment of cancer. Because cancer cells have multiple resistance mechanisms, it is important to understand the downstream pathways of the target genes and monitor the pharmacodynamic markers associated with therapeutic efficacy. We performed a transcriptome analysis to characterize the response of various cancer cell lines to a selective fibroblast growth factor receptor (FGFR) inhibitor (CH5183284/Debio 1347), a mitogen-activated protein kinase kinase (MEK) inhibitor, or a phosphoinositide 3-kinase (PI3K) inhibitor. FGFR and MEK inhibition produced similar expression patterns, and the extracellular signal-regulated kinase (ERK) gene signature was altered in several FGFR inhibitor-sensitive cell lines. Consistent with these findings, CH5183284/Debio 1347 suppressed phospho-ERK in every tested FGFR inhibitor-sensitive cell line. Because the mitogen-activated protein kinase (MAPK) pathway functions downstream of FGFR, we searched for a pharmacodynamic marker of FGFR inhibitor efficacy in a collection of cell lines with the ERK signature and identified dual-specificity phosphatase 6 (DUSP6) as a candidate marker. Although a MEK inhibitor suppressed the MAPK pathway, most FGFR inhibitor-sensitive cell lines are insensitive to MEK inhibitors and we found potent feedback activation of several pathways via FGFR. We therefore suggest that FGFR inhibitors exert their effect by suppressing ERK signaling without feedback activation. In addition, DUSP6 may be a pharmacodynamic marker of FGFR inhibitor efficacy in FGFR-addicted cancers.

  6. COX-2 FROM THE INJURY MILIEU IS CRITICAL FOR THE INITIATION OF PERIOSTEAL PROGENITOR CELL MEDIATED BONE HEALING

    PubMed Central

    Xie, Chao; Ming, Xue; Wang, Qun; Schwarz, Edward M.; Guldberg, Robert E.; O’Keefe, Regis J.; Zhang, Xinping

    2009-01-01

    Although a critical role of COX-2 in bone repair has been established, the mechanism involved remains unclear. During early inflammatory phase of bone healing, COX-2 is produced by the surrounding inflammatory cells as well as bone/cartilage progenitors. Based on the temporal and spatial expression of COX-2 during the early phase of fracture healing, we hypothesize that COX-2 from both sources is critical for progenitor cell activation, proliferation and differentiation. To directly test this we utilized a murine femoral grafting model, in which live segmental grafts from the same strains were transplanted and donor versus host cell involvement in healing was assessed. Specifically, fresh femur cortical bone grafts of 4-mm in length from COX-2-/- (KO) mice were transplanted into wild type (WT) mice with the same sized segmental defect in femurs. Similarly, grafts from WT were transplanted into the defects in KO mice. As controls, transplantations between wild types, and transplantations between KO were also performed. Histologic analyses showed that WT-to-WT transplantation resulted in normal endochondral bone healing as evidenced by markedly induction of neovascularization and periosteal bone formation on donor graft. In contrast, transplantation of KO graft into KO host led to 96 % reduction of bone formation and near elimination of donor cell-initiated periosteal bone formation. Similarly, transplantation of WT graft into a KO host resulted in 87% reduction of bone formation (n=8, p>0.05), indicating that KO host impaired WT donor progenitor cell expansion and differentiation. When a KO graft was transplanted into WT host, KO donor periosteal cell-initiated endochondral bone formation was restored. Histomorphometric analyses demonstrated 10-fold increase in bone formation and 3-fold increase in cartilage formation compared to KO-to-KO transplantation (n=8, p<0.05), suggesting that COX-2 deficient donor cells were capable to differentiate and form bone when

  7. The ETS-Domain Transcription Factor Elk-1 Regulates COX-2 Gene Expression and Inhibits Glucose-Stimulated Insulin Secretion in the Pancreatic β -Cell Line INS-1.

    PubMed

    Zhang, Xiong-Fei; Zhu, Yi; Liang, Wen-Biao; Zhang, Jing-Jing

    2013-01-01

    Cyclooxygenase-2 (COX-2) expression is associated with many aspects of physiological and pathological conditions, including pancreatic β -cell dysfunction. Prostaglandin E2 (PGE2) production, as a consequence of COX-2 gene induction, has been reported to impair β -cell function. The molecular mechanisms involved in the regulation of COX-2 gene expression are not fully understood. We previously demonstrated that transcription factor Elk-1 significantly upregulated COX-2 gene promoter activity. In this report, we used pancreatic β -cell line (INS-1) to explore the relationships between Elk-1 and COX-2. We first investigated the effects of Elk-1 on COX-2 transcriptional regulation and expression in INS-1 cells. We thus undertook to study the binding of Elk-1 to its putative binding sites in the COX-2 promoter. We also analysed glucose-stimulated insulin secretion (GSIS) in INS-1 cells that overexpressed Elk-1. Our results demonstrate that Elk-1 efficiently upregulates COX-2 expression at least partly through directly binding to the -82/-69 region of COX-2 promoter. Overexpression of Elk-1 inhibits GSIS in INS-1 cells. These findings will be helpful for better understanding the transcriptional regulation of COX-2 in pancreatic β -cell. Moreover, Elk-1, the transcriptional regulator of COX-2 expression, will be a potential target for the prevention of β -cell dysfunction mediated by PGE2.

  8. JMJD2B is required for Helicobacter pylori-induced gastric carcinogenesis via regulating COX-2 expression.

    PubMed

    Han, Fengjuan; Ren, Juchao; Zhang, Jinjin; Sun, Yundong; Ma, Fang; Liu, Zhifang; Yu, Han; Jia, Jihui; Li, Wenjuan

    2016-06-21

    Helicobacter pylori (H. pylori) infection is the strongest risk factor for the initiation and progression of gastric cancer. However, the mechanism of H. pylori-induced pathogenesis remains unclear. In this study, we investigate the role of H. pylori infection in JMJD2B upregulation and the mechanism underlying gastric carcinogenesis. We find that JMJD2B can be induced by H. pylori infection via β-catenin pathway. β-catenin directly binds to JMJD2B promoter and stimulates JMJD2B expression following H. pylori infection. Increased JMJD2B, together with NF-κB, binds to COX-2 promoter to enhance its transcription by demethylating H3K9me3 locally. JMJD2B and COX-2 expression is upregulated in H. pylori infected mice in vivo. Furthermore, JMJD2B and COX-2 expression is gradually increased in human gastric tissues from gastritis to gastric cancer. The level of JMJD2B and COX-2 in H. pylori-positive gastritis tissues is significantly higher than that in H. pylori-negative tissues. Moreover, a positive correlation between JMJD2B and COX-2 expression is found in both gastritis and gastric cancer tissues. Therefore, JMJD2B is a crucial factor in triggering H. pylori-induced chronic inflammation and progression of gastric carcinogenesis and it may serve as a novel target for the intervention of gastric cancer.

  9. Cooperation between COA6 and SCO2 in COX2 maturation during cytochrome c oxidase assembly links two mitochondrial cardiomyopathies.

    PubMed

    Pacheu-Grau, David; Bareth, Bettina; Dudek, Jan; Juris, Lisa; Vögtle, F-Nora; Wissel, Mirjam; Leary, Scot C; Dennerlein, Sven; Rehling, Peter; Deckers, Markus

    2015-06-02

    Three mitochondria-encoded subunits form the catalytic core of cytochrome c oxidase, the terminal enzyme of the respiratory chain. COX1 and COX2 contain heme and copper redox centers, which are integrated during assembly of the enzyme. Defects in this process lead to an enzyme deficiency and manifest as mitochondrial disorders in humans. Here we demonstrate that COA6 is specifically required for COX2 biogenesis. Absence of COA6 leads to fast turnover of newly synthesized COX2 and a concomitant reduction in cytochrome c oxidase levels. COA6 interacts transiently with the copper-containing catalytic domain of newly synthesized COX2. Interestingly, similar to the copper metallochaperone SCO2, loss of COA6 causes cardiomyopathy in humans. We show that COA6 and SCO2 interact and that corresponding pathogenic mutations in each protein affect complex formation. Our analyses define COA6 as a constituent of the mitochondrial copper relay system, linking defects in COX2 metallation to cardiac cytochrome c oxidase deficiency.

  10. JMJD2B is required for Helicobacter pylori-induced gastric carcinogenesis via regulating COX-2 expression

    PubMed Central

    Zhang, Jinjin; Sun, Yundong; Ma, Fang; Liu, Zhifang; Yu, Han; Jia, Jihui; Li, Wenjuan

    2016-01-01

    Helicobacter pylori (H. pylori) infection is the strongest risk factor for the initiation and progression of gastric cancer. However, the mechanism of H. pylori-induced pathogenesis remains unclear. In this study, we investigate the role of H. pylori infection in JMJD2B upregulation and the mechanism underlying gastric carcinogenesis. We find that JMJD2B can be induced by H. pylori infection via β-catenin pathway. β-catenin directly binds to JMJD2B promoter and stimulates JMJD2B expression following H. pylori infection. Increased JMJD2B, together with NF-κB, binds to COX-2 promoter to enhance its transcription by demethylating H3K9me3 locally. JMJD2B and COX-2 expression is upregulated in H. pylori infected mice in vivo. Furthermore, JMJD2B and COX-2 expression is gradually increased in human gastric tissues from gastritis to gastric cancer. The level of JMJD2B and COX-2 in H. pylori-positive gastritis tissues is significantly higher than that in H. pylori-negative tissues. Moreover, a positive correlation between JMJD2B and COX-2 expression is found in both gastritis and gastric cancer tissues. Therefore, JMJD2B is a crucial factor in triggering H. pylori-induced chronic inflammation and progression of gastric carcinogenesis and it may serve as a novel target for the intervention of gastric cancer. PMID:27232941

  11. Downregulation of HOTAIR Expression Mediated Anti-Metastatic Effect of Artesunate on Cervical Cancer by Inhibiting COX-2 Expression

    PubMed Central

    Zhang, Lixin; Qian, Hua; Sha, Min; Luan, Zhengyun; Lin, Mei; Yuan, Donglan; Li, Xiaokang; Huang, Junxing; Ye, Lihua

    2016-01-01

    Artesunate (ART) has anti-cancer activities for a variety of solid tumors. The aim of this study was to investigate the anti-metastatic effect of ART on cervical cancer cells. In vivo anti-metastatic effect of ART was investigated in mice with the lung metastasis model by the subcutaneous injection of ART. The interaction of HOTAIR and COX-2 was measured by RNA immunoprecipitation and RNA pull-down assay. The effect of ART on metastasis of CaSki and Hela cells was evaluated by invasion and migration assay. We found that ART inhibited cervical cancer metastasis and HOTAIR expression. HOTAIR overexpression partially abolished the anti-metastatic effect of ART on cervical cancer cells. In addition, HOTAIR can interact with COX-2 to positively regulate COX-2 expression and catalytic activity. Finally, overexpression of COX-2 reversed the effect of HOTAIR knockdown on Hela cell migration and invasion. Taken together, our data revealed that ART may elicit anti-metastatic effect against cervical cancer by inhibition of HOTAIR expression, which resulted in the decrease of COX-2 expression. PMID:27736969

  12. Synergistic COX2 Induction by IFNγ and TNFα Self-Limits Type-1 Immunity in the Human Tumor Microenvironment.

    PubMed

    Wong, Jeffrey L; Obermajer, Nataša; Odunsi, Kunle; Edwards, Robert P; Kalinski, Pawel

    2016-04-01

    Maintenance of CTL-, Th1-, and NK cell-mediated type-1 immunity is essential for effective antitumor responses. Unexpectedly, we observed that the critical soluble mediators of type-1 immune effector cells, IFNγ and TNFα, synergize in the induction of cyclooxygenase 2 (COX2), the key enzyme in prostaglandin (PG)E2 synthesis, and the subsequent hyperactivation of myeloid-derived suppressor cells (MDSC) within the tumor microenvironment (TME) of ovarian cancer patients. MDSC hyperactivation by type-1 immunity and the resultant overexpression of indoleamine 2,3-dioxygenase (IDO), inducible nitric oxide synthase (iNOS/NOS2), IL10, and additional COX2 result in strong feedback suppression of type-1 immune responses. This paradoxical immune suppression driven by type-1 immune cell activation was found to depend on the synergistic action of IFNγ and TNFα, and could not be reproduced by either of these factors alone. Importantly, from a therapeutic standpoint, these negative feedback limiting type-1 responses could be eliminated by COX2 blockade, allowing amplification of type-1 immunity in the ovarian cancer TME. Our data demonstrate a new mechanism underlying the self-limiting nature of type-1 immunity in the human TME, driven by the synergistic induction of COX2 by IFNγ and TNFα, and provide a rationale for targeting the COX2-PGE2 axis to enhance the effectiveness of cancer immunotherapies.

  13. Pulmonary cyclooxygenase-1 (COX-1) and COX-2 cellular expression and distribution after respiratory syncytial virus and parainfluenza virus infection.

    PubMed

    Radi, Zaher A; Meyerholz, David K; Ackermann, Mark R

    2010-02-01

    Prostaglandins (PGs) play an important role in pulmonary physiology and various pathophysiological processes following infection. The initial step in the biosynthesis of PGs is regulated by two distinct cyclooxygenase enzymes, cyclooxygenase-1 (COX-1) and COX-2. The goal of this study was to investigate the pulmonary cellular localization and distribution of COX-1 and COX-2 in a neonatal lamb model following respiratory syncytial virus (RSV) and parainfluenza virus 3 (PI3) infection, organisms that also cause significant respiratory disease in children. No significant differences were seen in pulmonary COX-1 expression at various microanatomical locations following RSV or PI3 infection compared to controls. In contrast, COX-2 was upregulated following RSV and PI3 infection. Strong expression was restricted to bronchial and bronchiolar epithelial cells and macrophages, while minimal expression was present in the same microanatomical locations in the uninfected lungs. Other microanatomical locations in both the controls and the infected lungs lacked expression. This work suggests that during RSV or PI3 infection: (1) COX-1 cellular expression is not altered, (2) COX-2 cellular expression is upregulated in airway bronchiolar and bronchial epithelial cells and macrophages, (3) respiratory epithelium along with macrophages are important microanatomical compartments regulating the host inflammatory response during viral infection, and (4) COX-2 may be a potential target for RSV and PI3 therapy.

  14. Mechanism-Based Inhibitors of Serine Proteases with High Selectivity Through Optimization of S’ Subsite Binding

    PubMed Central

    Li, Yi; Dou, Dengfeng; He, Guijia; Lushington, Gerald H.; Groutas, William C.

    2009-01-01

    A series of mechanism-based inhibitors designed to interact with the S’ subsites of serine proteases was synthesized and their inhibitory activity toward the closely-related serine proteases human neutrophil elastase (HNE) and proteinase 3 (PR 3) was investigated. The compounds were found to be time-dependent inhibitors of HNE and were devoid of any inhibitory activity toward PR 3. The results suggest that highly selective inhibitors of serine proteases whose primary substrate specificity and active sites are similar can be identified by exploiting differences in their S’ subsites. The best inhibitor (compound 16) had a kinact/KI value of 4580 M−1 s−1. PMID:19394830

  15. Selective Serotonin Reuptake Inhibitors and Violent Crime: A Cohort Study

    PubMed Central

    Molero, Yasmina; Lichtenstein, Paul; Zetterqvist, Johan; Gumpert, Clara Hellner; Fazel, Seena

    2015-01-01

    Background Although selective serotonin reuptake inhibitors (SSRIs) are widely prescribed, associations with violence are uncertain. Methods and Findings From Swedish national registers we extracted information on 856,493 individuals who were prescribed SSRIs, and subsequent violent crimes during 2006 through 2009. We used stratified Cox regression analyses to compare the rate of violent crime while individuals were prescribed these medications with the rate in the same individuals while not receiving medication. Adjustments were made for other psychotropic medications. Information on all medications was extracted from the Swedish Prescribed Drug Register, with complete national data on all dispensed medications. Information on violent crime convictions was extracted from the Swedish national crime register. Using within-individual models, there was an overall association between SSRIs and violent crime convictions (hazard ratio [HR] = 1.19, 95% CI 1.08–1.32, p < 0.001, absolute risk = 1.0%). With age stratification, there was a significant association between SSRIs and violent crime convictions for individuals aged 15 to 24 y (HR = 1.43, 95% CI 1.19–1.73, p < 0.001, absolute risk = 3.0%). However, there were no significant associations in those aged 25–34 y (HR = 1.20, 95% CI 0.95–1.52, p = 0.125, absolute risk = 1.6%), in those aged 35–44 y (HR = 1.06, 95% CI 0.83–1.35, p = 0.666, absolute risk = 1.2%), or in those aged 45 y or older (HR = 1.07, 95% CI 0.84–1.35, p = 0.594, absolute risk = 0.3%). Associations in those aged 15 to 24 y were also found for violent crime arrests with preliminary investigations (HR = 1.28, 95% CI 1.16–1.41, p < 0.001), non-violent crime convictions (HR = 1.22, 95% CI 1.10–1.34, p < 0.001), non-violent crime arrests (HR = 1.13, 95% CI 1.07–1.20, p < 0.001), non-fatal injuries from accidents (HR = 1.29, 95% CI 1.22–1.36, p < 0.001), and emergency inpatient or outpatient treatment for alcohol intoxication or misuse

  16. Relationship of the Topological Distances and Activities between mPGES-1 and COX-2 versus COX-1: Implications of the Different Post-Translational Endoplasmic Reticulum Organizations of COX-1 and COX-2.

    PubMed

    Akasaka, Hironari; So, Shui-Ping; Ruan, Ke-He

    2015-06-16

    In vascular inflammation, prostaglandin E2 (PGE₂) is largely biosynthesized by microsomal PGE₂ synthase-1 (mPGES-1), competing with other downstream eicosanoid-synthesizing enzymes, such as PGIS, a synthase of a vascular protector prostacyclin (PGI₂), to isomerize the cyclooxygenase (COX)-2-derived prostaglandin H2 (PGH₂). In this study, we found that a majority of the product from the cells co-expressing human COX-2, mPGES-1, and PGIS was PGE₂. We hypothesize that the molecular and cellular mechanisms are related to the post-translational endoplasmic reticulum (ER) arrangement of those enzymes. A set of fusion enzymes, COX-2-linker [10 amino acids (aa)]-PGIS and COX-2-linker (22 amino acids)-PGIS, were created as "The Bioruler", in which the 10 and 22 amino acids are defined linkers with known helical structures and distances (14.4 and 30.8 Å, respectively). Our experiments have shown that the efficiency of PGI₂ biosynthesis was reduced when the separation distance increased from 10 to 22 amino acids. When COX-2-10aa-PGIS (with a 14.4 Å separation) was co-expressed with mPGES-1 on the ER membrane, a major product was PGE₂, but not PGI₂. However, expression of COX-2-10aa-PGIS and mPGES-1 on a separated ER with a distance of ≫30.8 Å reduced the level of PGE₂ production. These data indicated that the mPGES-1 is "complex-likely" colocalized with COX-2 within a distance of 14.4 Å. In addition, the cells co-expressing COX-1-10aa-PGIS and mPGES-1 produced PGI₂ mainly, but not PGE₂. This indicates that mPGES-1 is expressed much farther from COX-1. These findings have led to proposed models showing the different post-translational ER organization between COX-2 and COX-1 with respect to the topological arrangement of the mPGES-1 during vascular inflammation.

  17. Selective histone deacetylase 6 inhibitors bearing substituted urea linkers inhibit melanoma cell growth

    PubMed Central

    Bergman, Joel A.; Woan, Karrune; Perez-Villarroel, Patricio; Villagra, Alejandro; Sotomayor, Eduardo M.; Kozikowski, Alan P.

    2012-01-01

    The incidence of malignant melanoma has dramatically increased in recent years thus requiring the need for improved therapeutic strategies. In our efforts to design selective histone deactylase inhibitors (HDACI), we discovered that the aryl urea 1 is a modestly potent yet non-selective inhibitor. Structure activity relationship studies revealed that adding substituents to the nitrogen atom of the urea so as to generate compounds bearing a branched linker group results in increased potency and selectivity for HDAC6. Compound 5g shows low nanomolar inhibitory potency against HDAC6 and a selectivity of ~600-fold relative to the inhibition of HDAC1. These HDACIs were evaluated for their ability to inhibit the growth of B16 melanoma cells with the most potent and selective HDAC6I being found to decrease tumor cell growth. To the best of our knowledge, this work constitutes the first report of HDAC6 selective inhibitors that possess antiproliferative effects against melanoma cells. PMID:23009203

  18. Evaluation of NHS Carbamates as a Potent and Selective Class of Endocannabinoid Hydrolase Inhibitors

    PubMed Central

    2013-01-01

    Monoacylglycerol lipase (MAGL) is a principal metabolic enzyme responsible for hydrolyzing the endogenous cannabinoid (endocannabinoid) 2-arachidonoylglycerol (2-AG). Selective inhibitors of MAGL offer valuable probes to further understand the enzyme’s function in biological systems and may lead to drugs for treating a variety of diseases, including psychiatric disorders, neuroinflammation, and pain. N-Hydroxysuccinimidyl (NHS) carbamates have recently been identified as a promising class of serine hydrolase inhibitors that shows minimal cross-reactivity with other proteins in the proteome. Here, we explore NHS carbamates more broadly and demonstrate their potential as inhibitors of endocannabinoid hydrolases and additional enzymes from the serine hydrolase class. We extensively characterize an NHS carbamate 1a (MJN110) as a potent, selective, and in-vivo-active MAGL inhibitor. Finally, we demonstrate that MJN110 alleviates mechanical allodynia in a rat model of diabetic neuropathy, marking NHS carbamates as a promising class of MAGL inhibitors. PMID:23731016

  19. Structural characterizations of nonpeptidic thiadiazole inhibitors of matrix metalloproteinases reveal the basis for stromelysin selectivity.

    PubMed Central

    Finzel, B. C.; Baldwin, E. T.; Bryant, G. L.; Hess, G. F.; Wilks, J. W.; Trepod, C. M.; Mott, J. E.; Marshall, V. P.; Petzold, G. L.; Poorman, R. A.; O'Sullivan, T. J.; Schostarez, H. J.; Mitchell, M. A.

    1998-01-01

    The binding of two 5-substituted-1,3,4-thiadiazole-2-thione inhibitors to the matrix metalloproteinase stromelysin (MMP-3) have been characterized by protein crystallography. Both inhibitors coordinate to the catalytic zinc cation via an exocyclic sulfur and lay in an unusual position across the unprimed (P1-P3) side of the proteinase active site. Nitrogen atoms in the thiadiazole moiety make specific hydrogen bond interactions with enzyme structural elements that are conserved across all enzymes in the matrix metalloproteinase class. Strong hydrophobic interactions between the inhibitors and the side chain of tyrosine-155 appear to be responsible for the very high selectivity of these inhibitors for stromelysin. In these enzyme/inhibitor complexes, the S1' enzyme subsite is unoccupied. A conformational rearrangement of the catalytic domain occurs that reveals an inherent flexibility of the substrate binding region leading to speculation about a possible mechanism for modulation of stromelysin activity and selectivity. PMID:9792098

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

    PubMed

    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.

  1. Selective inhibitors of the Janus kinase Jak3--Are they effective?

    PubMed

    Thoma, Gebhard; Drückes, Peter; Zerwes, Hans-Günter

    2014-10-01

    Jak3, together with Jak1, is involved in signal transduction initiated by cytokines signaling through the common gamma chain which are important in immune homeostasis and immune pathologies. Based on genetic evidence Jak3 has been considered to be an attractive target for immunosuppression. The Jak inhibitor tofacitinib (CP-690,550) which is an approved drug for rheumatoid arthritis was originally introduced as a selective Jak3 inhibitor, however, it also inhibits Jak1 and Jak2. The search for new selective Jak3 inhibitors has yielded several compounds whose profiles will be reviewed here. Implications on Jak3 as a therapeutic target are also discussed.

  2. Palladium-Catalyzed Arylation of Carbasugars Enables the Discovery of Potent and Selective SGLT2 Inhibitors.

    PubMed

    Ng, Wai-Lung; Lau, Kit-Man; Lau, Clara B-S; Shing, Tony K M

    2016-10-24

    Selective inhibition of the transporter protein sodium-glucose cotransporter 2 (SGLT2) has emerged as a promising way to control blood glucose level in diabetes patients. Reported herein is a short and convergent synthetic route towards some small-molecule SGLT2 inhibitors by a chemo- and diastereospecific palladium-catalyzed arylation reaction. This synthetic strategy enabled the discovery of two highly selective and potent SGLT2 inhibitors, thereby paving the way towards the development of carbasugar SGLT2 inhibitors as potential antidiabetic/antitumor agents.

  3. Discovery of GSK2656157: An Optimized PERK Inhibitor Selected for Preclinical Development.

    PubMed

    Axten, Jeffrey M; Romeril, Stuart P; Shu, Arthur; Ralph, Jeffrey; Medina, Jesús R; Feng, Yanhong; Li, William Hoi Hong; Grant, Seth W; Heerding, Dirk A; Minthorn, Elisabeth; Mencken, Thomas; Gaul, Nathan; Goetz, Aaron; Stanley, Thomas; Hassell, Annie M; Gampe, Robert T; Atkins, Charity; Kumar, Rakesh

    2013-10-10

    We recently reported the discovery of GSK2606414 (1), a selective first in class inhibitor of protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), which inhibited PERK activation in cells and demonstrated tumor growth inhibition in a human tumor xenograft in mice. In continuation of our drug discovery program, we applied a strategy to decrease inhibitor lipophilicity as a means to improve physical properties and pharmacokinetics. This report describes our medicinal chemistry optimization culminating in the discovery of the PERK inhibitor GSK2656157 (6), which was selected for advancement to preclinical development.

  4. Use of selective-serotonin reuptake inhibitors and platelet aggregation inhibitors among individuals with co-occurring atherosclerotic cardiovascular disease and depression or anxiety

    PubMed Central

    Thornton, J Douglas; Agarwal, Parul; Sambamoorthi, Usha

    2016-01-01

    Objective: Medications commonly used to treat heart disease, anxiety, and depression can interact resulting in an increased risk of bleeding, warranting a cautious approach in medical decision making. This retrospective, descriptive study examined the prevalence and the factors associated with the use of both selective-serotonin reuptake inhibitor and platelet aggregation inhibitor among individuals with co-occurring atherosclerotic cardiovascular disease and anxiety or depression. Methods: Respondents aged 22 years and older, alive throughout the study period, and diagnosed with co-occurring atherosclerotic cardiovascular disease and anxiety or depression (n = 1507) in years 2007 through 2013 of the Medical Expenditures Panel Survey were included. The use of treatment was grouped as follows: selective-serotonin reuptake inhibitor and platelet aggregation inhibitor, selective-serotonin reuptake inhibitor or platelet aggregation inhibitor, and neither selective-serotonin reuptake inhibitor nor platelet aggregation inhibitor. Results: Overall, 16.5% used both selective-serotonin reuptake inhibitor and platelet aggregation inhibitor, 61.2% used selective-serotonin reuptake inhibitor or platelet aggregation inhibitor, and 22.3% used neither selective-serotonin reuptake inhibitor nor platelet aggregation inhibitor. Respondents aged over 65 years (adjusted odds ratio = 1.93 (95% confidence interval = 1.08–3.45)) and having a diagnosis of diabetes (adjusted odds ratio = 1.63 (95% confidence interval = 1.15–2.31)) and hypertension (adjusted odds ratio = 1.84 (95% confidence interval = 1.04–3.27)) were more likely to be prescribed the combination. Conclusion: The drug interaction was prevalent in patients who are already at higher risk of health disparities and worse outcomes thus requiring vigilant evaluation. PMID:28348738

  5. Selective and potent furin inhibitors protect cells from anthrax without significant toxicity.

    PubMed

    Remacle, Albert G; Gawlik, Katarzyna; Golubkov, Vladislav S; Cadwell, Gregory W; Liddington, Robert C; Cieplak, Piotr; Millis, Sherri Z; Desjardins, Roxane; Routhier, Sophie; Yuan, Xue Wen; Neugebauer, Witold A; Day, Robert; Strongin, Alex Y

    2010-06-01

    Furin and related proprotein convertases cleave the multibasic motifs R-X-R/K/X-R in the precursor proteins and, as a result, transform the latent proproteins into biologically active proteins and peptides. Furin is present both in the intracellular secretory pathway and at the cell surface. Intracellular furin processes its multiple normal cellular targets in the Golgi and secretory vesicle compartments while cell-surface furin appears to be essential only for the processing of certain pathogenic proteins and, importantly, anthrax. To design potent, safe and selective inhibitors of furin, we evaluated the potency and selectivity of the derivatized peptidic inhibitors modeled from the extended furin cleavage sequence of avian influenza A H5N1. We determined that the N- and C-terminal modifications of the original RARRRKKRT inhibitory scaffold produced selective and potent, nanomolar range, inhibitors of furin. These inhibitors did not interfere with the normal cellular function of furin because of the likely functional redundancy existing between furin and other proprotein convertases. These furin inhibitors, however, were highly potent in blocking the furin-dependent cell-surface processing of anthrax protective antigen-83 both in vitro and cell-based assays and in vivo. We conclude that the inhibitors we have designed have a promising potential as selective anthrax inhibitors, without affecting major cell functions.

  6. Flowers of Clerodendrum volubile exacerbate immunomodulation by suppressing phagocytic oxidative burst and modulation of COX-2 activity.

    PubMed

    Erukainure, Ochuko L; Mesaik, Ahmed M; Muhammad, Aliyu; Chukwuma, Chika I; Manhas, Neha; Singh, Parvesh; Aremu, Oluwole S; Islam, Md Shahidul

    2016-10-01

    The immunomodulatory potentials of the crude methanolic extract and fractions [n-hexane (Hex), n-dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol (BuOH)] of Clerodendrum volubile flowers were investigated on whole blood phagocytic oxidative burst using luminol-amplified chemiluminescence technique. They were also investigated for their free radicals scavenging activities. The DCM fraction showed significant (p<0.05) anti-oxidative burst and free radical scavenging activities indicating high immunomodulatory and antioxidant potencies respectively. Cytotoxicity assay of the DCM fraction revealed a cytotoxic effect on CC-1 normal cell line. GCMS analysis revealed the presence of triacetin; 3,6-dimethyl-3-octanol; 2R - Acetoxymethyl-1,3,3-trimethtyl - 4t - (3-methyl-2-buten-1-yl) - 1c - cyclohexanol and Stigmastan - 3,5-diene in DCM fraction. These compounds were docked with the active sites of cyclooxygenase-2 (COX-2). Triacetin, 3,6-dimethyl-3-Octanol, and 2R-Acetoxymethyl-1,3,3-trimethtyl-4t-(3-methyl-2-buten-