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1

Is COX-2 a perpetrator or a protector? Selective COX-2 inhibitors remain controversial.  

PubMed

COX-2(cyclooxygenase-2) has sparked a surge in pharmaceutical interest since its discovery at the beginning of the 1990s. Several COX-2 selective inhibitors that avoid gastrointestinal side effects have been successfully launched into the market in recent years. The first selective COX-2 inhibitor, celecoxib, entered the market in December 1998 [corrected] However, there are a few organs that physiologically and functionally express COX-2, particularly the glomeruli of the kidney and the cortex of the brain. Inhibition of COX-2 expression in these organs possibly causes heart attack and stroke in long-term COX-2 inhibitor users. Recently, a USA Food and Drug Agency (FDA) advisory panel re-evaluated COX-2 inhibitors and unanimously concluded that the entire class of COX-2 inhibitors increase the risk of cardiovascular problems. Thus the use of COX-2 inhibitors is still controversial, and there is a challenge for not only pharmacologists, but also the pharmaceutical industry, to develop improved painkilling and anti-inflammatory drugs. This may involve exploring a new generation of COX-2 inhibitors with different inhibitory mechanisms through computer-aided design, screening different sources of inhibitors with lower selectivity, or seeking completely new targets. Synthetic COX-2 inhibitors have high selectivity and the advantage of irreversible inhibition, whereas naturally derived COX-2 inhibitors have lower selectivity and fewer side effects, with the medical effects in general not being as striking as those achieved using synthetic inhibitors. This review discusses the mechanism of COX-2 inhibitor therapy and a possible new way of exploration in the development of anti-inflammatory, analgetic, and antipyretic drugs. PMID:16038624

Luo, Cheng; He, Ming-liang; Bohlin, Lars

2005-08-01

2

The 2?-Trifluoromethyl Analogue of Indomethacin Is a Potent and Selective COX-2 Inhibitor  

PubMed Central

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 ?M). 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.

2013-01-01

3

Inhibition of COX in ocular tissues: an in vitro model to identify selective COX-2 inhibitors.  

PubMed

The aim of this work was to study the regulation of LPS-stimulated PGE 2 synthesis by traditional NSAIDs (piroxicam and diclofenac) and a selective COX-2 inhibitor (NS-398), in cultured bovine corneal endothelial cells and retinal pigmentary epithelial cells. The IC50 values of piroxicam and diclofenac were compared with IC50 values of NS-398, diclofenac, in both types of cells, showed higher potency than piroxicam. Diclofenac seemed to be a COX-2 inhibitor because its IC50 values were similar to the IC50 values of NS-398. We suggest that this in vitro cell assay system could be useful for identifying compounds that selectively inhibit COX-2 in ocular tissues. PMID:11322639

García-Cabanes, C; Palmero, M; Bellot, J L; Castillo, M; Orts, A

2001-02-01

4

Selective COX-2 inhibitors, NSAIDs and congestive heart failure: differences between new and recurrent cases  

PubMed Central

AIMS To quantify the association between treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) and selective cyclooxygenase (COX)-2 inhibitors and hospitalization due to congestive heart failure (CHF); to determine if the risk varies between first and subsequent episodes of CHF. METHODS We conducted a case–control study of the relationship between recent use of NSAIDs and COX-2 inhibitors and hospitalization with CHF. Cases (n = 530) were patients admitted to hospital with a primary diagnosis of CHF. Controls (n = 1054) were subjects without CHF who were admitted to the same hospitals as the cases. They were frequency matched to cases on the basis of age and sex. Structured interviews were used to obtain information on a number of study factors, including recent use of NSAIDs and COX-2 inhibitors. Relative risks (RRs) were estimated from exposure odds ratios, adjusted for a range of potential confounders. RESULTS Overall, NSAIDs and COX-2 inhibitors had been taken by 249 (23.6%) controls in the week before admission to hospital. Use of any NSAID/COX-2 inhibitor was recorded in 81/285 (28.4%) first-time cases compared with 38/245 (15.5%) in recurrent cases: difference 12.9% (95% confidence interval 5.9, 19.8) (P = 0.0004). The adjusted RRs for first hospital admission for CHF with different drug exposures were: NSAIDs 1.1 (0.67, 1.83), rofecoxib 1.29 (0.78, 2.13) and celecoxib 1.47 (0.85, 2.53). CONCLUSIONS We found weak and statistically nonsignificant associations between use of NSAIDs and COX-2 inhibitors and hospitalization with CHF. This low RR is consistent with the results of recently published studies, but not with early studies that found an approximate doubling of risk with use of NSAIDs. The dilution of risk and the significantly lower levels of prescribing for recurrent than for first-time cases of heart failure suggest that prescribing doctors heeded messages that NSAIDs may precipitate CHF in vulnerable individuals, and that they have applied the same message to selective COX-2 inhibitors. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT Pharmaco-epidemiological studies have shown that in susceptible individuals, nonsteroidal anti-inflammatory drugs (NSAIDs) and selective cyclooxygenase (COX)-2 inhibitors increase the risk of developing congestive heart failure (CHF). Recently published studies have found lower relative risk (RR) estimates than the initial studies published in 1998–2000. It is unclear whether the level of risk is elevated equally in first time and recurrent cases of CHF. WHAT THIS STUDY ADDS This study found low-level, statistically nonsignificant elevations of risk with NSAIDs and COX-2 inhibitors.There was a much higher level of recent use of NSAIDs/COX-2 inhibitors among first-time cases than among recurrent cases of CHF.The dilution of the RR over successive studies, and the differences between first-time and recurrent cases noted here, suggest that prescribing doctors have heeded advice about the cardiovascular risks of NSAIDs and extended this practice to selective COX-2 inhibitors.

McGettigan, Patricia; Han, Pearline; Jones, Lisa; Whitaker, Diana; Henry, David

2008-01-01

5

Inhibition of Ion Channels and Heart Beat in Drosophila by Selective COX-2 Inhibitor SC-791  

PubMed Central

Recent findings suggest that modulation of ion channels might be implicated in some of the clinical effects of coxibs, selective inhibitors of cyclooxygenase-2 (COX-2). Celecoxib and its inactive analog 2,5-dimethyl-celecoxib, but not rofecoxib, can suppress or augment ionic currents and alter functioning of neurons and myocytes. To better understand these unexpected effects, we have recently investigated the mechanism of inhibition of human Kv2.1 channels by a highly selective COX-2 inhibitor SC-791. In this study we have further explored the SC-791 action on ion channels and heartbeat in Drosophila, which lacks cyclooxygenases and thus can serve as a convenient model to study COX-2-independent mechanisms of coxibs. Using intracellular recordings in combination with a pharmacological approach and utilizing available Drosophila mutants, we found that SC-791 inhibited voltage-activated K+ and L-type Ca2+ channels in larval body-wall muscles and reduced heart rate in a concentration-dependent manner. Unlike celecoxib and several other K+ channel blockers, SC-791 did not induce arrhythmia. Instead, application of SC-791 resulted in a dramatic slowing of contractions and, at higher concentrations, in progressively weaker contractions with gradual cessation of heartbeat. Isradipine, a selective blocker of L-type Ca2+ channels, showed a similar pattern of heart arrest, though no prolongation of contractions was observed. Ryanodine was the only channel modulating compound of those tested additionally that was capable of slowing contractions. Like SC-791, ryanodine reduced heart rate without arrhythmia. However, it could not stop heartbeat completely even at 500 µM, the highest concentration used. The magnitude of heart rate reduction, when SC-791 and ryanodine were applied together, was smaller than expected for independent mechanisms, raising the possibility that SC-791 might be interfering with excitation-contraction coupling in Drosophila heart.

Frolov, Roman V.; Singh, Satpal

2012-01-01

6

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

PubMed

1. DFU (5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl)phenyl-2(5H)-furan one) was identified as a novel orally active and highly selective cyclo-oxygenase-2 (COX-2) inhibitor. 2. 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 microM). 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 microM and 4.1 +/- 1.7 nM, respectively). 3. DFU caused a time-dependent inhibition of purified recombinant human COX-2 with a Ki, value of 140 +/- 68 microM for the initial reversible binding to enzyme and a kappa 2 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 microM 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. 4. Inhibition of purified recombinant human COX-1 by DFU was very weak and observed only at low concentrations of substrate (IC50 = 63 +/- 5 microM at 0.1 microM 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. 5. DFU inhibited lipopolysaccharide (LPS)-induced PGE2 production (COX-2) in a human whole blood assay with a potency (IC50 = 0.28 +/- 0.04 microM) similar to indomethacin (IC50 = 0.68 +/- 0.17 microM). In contrast, DFU was at least 500 times less potent (IC50 > 97 microM) than indomethacin at inhibiting coagulation-induced TXB2 production (COX-1) (IC50 = 0.19 +/- 0.02 microM). 6. In a sensitive assay with U937 cell microsomes at a low arachidonic acid concentration (0.1 microM), DFU inhibited COX-1 with an IC50 value of 13 +/- 2 microM as compared to 20 +/- 1 nM for indomethacin. CGP 28238, etodolac and SC-58125 were about 10 times more potent inhibitors of COX-1 than DFU. The order of potency of various inhibitors was diclofenac > indomethacin approximately naproxen > nimesulide approximately meloxicam approximately piroxicam > NS-398 approximately SC-57666 > SC-58125 > CGP 28238 approximately etodolac > L-745,337 > DFU. 7. DFU inhibited dose-dependently both the carrageenan-induced rat paw oedema (ED50 of 1.1 mg kg-1 vs 2.0 mg kg-1 for indomethacin) and hyperalgesia (ED50 of 0.95 mg kg-1 vs 1.5 mg kg-1 for indomethacin). The compound was also effective at reversing LPS-induced pyrexia in rats (ED50 = 0.76 mg kg-1 vs 1.1 mg kg-1 for indomethacin). 8. In a sensitive model in which 51Cr faecal excretion was used to assess the integrity of the gastrointestinal tract in rats, no significant effect was detected after oral administration of DFU (100 mg kg-1, b.i.d.) for 5 days, whereas chromium leakage was observed with lower doses of diclofenac (3 mg kg-1), meloxicam (3 mg kg-1) or etodolac (10-30 mg kg-1). A 5 day administration of DFU in squirrel monkeys (100 mg kg-1) did not affect chromium leakage in contrast to diclofenac (1 mg kg-1) or naproxen (5 mg kg-1). 9. The results indicate that COX-1 inhibitory effects can be detected for all selective COX-2 inhibitors tested by use of a sensitive assay at low substrate concentration. The novel inhibitor DFU shows the lowest inhibitory potency against COX-1, a consistent high selectivity of inhibition of COX-2 over COX-1 (>300 fold) with enzyme, whole cell and whole blood assays, with n

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; Chan, C C

1997-05-01

7

Design and synthesis of new 1,3-benzdiazinan-4-one derivatives as selective cyclooxygenase (COX-2) inhibitors.  

PubMed

A new group of regioisomeric 2,3-diaryl-1,3-benzdiazinan-4-ones, possessing a methyl sulfonyl pharmacophore, were synthesized and their biological activities were tested for cyclooxygenase-2 (COX-2) inhibitory activity. In vitro COX-1/COX-2 inhibition studies identified 3-(p-fluorophenyl)-2-(4-methylsulfonylphenyl)-1,3-benzdiazinane-4-one (2b) as a potent and highly selective (IC(50) = 0.07 µM; selectivity index = 572.8) COX-2 inhibitor. PMID:22076641

Zarghi, Afshin; Zebardast, Tannaz; Hajighasemali, Fatemeh; Alipoor, Eskandar; Daraie, Bahram; Hedayati, Mehdi

2012-04-01

8

Selective COX-2 inhibitors and dual acting anti-inflammatory drugs: critical remarks.  

PubMed

Non steroidal anti-inflammatory drugs (NSAIDs) are still the most commonly used remedies for rheumatic diseases. But NSAIDs produce serious adverse effects, the most important being gastric injury up to gastric ulceration and renal damage. Several strategies have been adopted in order to avoid these shortcomings, especially gastrointestinal toxicity. So, non steroidal anti-inflammatory drugs have been associated with gastroprotective agents that counteract the damaging effects of prostaglandin synthesis suppression: however, a combination therapy introduces problems of pharmacokinetics, toxicity, and patient s compliance. Also incorporation of a nitric oxide (NO)-generating moiety into the molecule of several NSAIDs was shown to greatly attenuate their ulcerogenic activity: however, several findings suggest a possible involvement of NO in the pathogenesis of arthritis and subsequent tissue destruction. A most promising approach seemed to be the preparation of novel NSAIDs, specific for the inducible isoform of cyclooxygenase (COX-2): they appear to be devoid of gastrointestinal toxicity, in that they spare mucosal prostaglandin synthesis. However, a number of recent studies raised serious questions about the two central tenets that support this approach, namely that the prostaglandins that mediate inflammation and pain are produced solely via COX-2 and that the prostaglandins that are important in gastrointestinal and renal function are produced solely via COX-1. So, increasing evidence shows that COX-2 (not only COX-1) also plays a physiological role in several body functions and that, conversely, COX-1 (not only COX-2) may also be induced at sites of inflammation. Moreover, COX-2 selective NSAIDs have lost the cardiovascular protective effects of non-selective NSAIDs, effects which are mediated through COX-1 inhibition (in addition, COX-2 has a role in sustaining vascular prostacyclin production). The products generated by the 5-lipoxygenase pathway (leukotrienes) are particularly important in inflammation: indeed, leukotrienes increase microvascular permeability and are potent chemotactic agents; moreover, inhibition of 5-lipoxygenase indirectly reduces the expression of TNF-alpha (a cytokine that plays a key role in inflammation). This explains the efforts to obtain drugs able to inhibit both 5-lipoxygenase and cyclooxygenases: the so-called dual acting anti-inflammatory drugs. Such compounds retain the activity of classical NSAIDs, while avoiding their main drawbacks, in that curtailed production of gastroprotective prostaglandins is associated with a concurrent curtailed production of the gastro-damaging and bronchoconstrictive leukotrienes. Moreover, thanks to their mechanism of action, dual acting anti-inflammatory drugs could not merely alleviate symptoms of rheumatic diseases, but might also satisfy, at least in part, the criteria of curative drugs. Indeed, leukotrienes are pro-inflammatory, increase microvascular permeability, are potent chemotactic agents and attract eosinophils, neutrophils and monocytes into the synovium. Finally, recent data strongly suggest that dual inhibitors may have specific protective activity also in neurodegeneration. PMID:12733982

Bertolini, A; Ottani, A; Sandrini, M

2002-05-01

9

Pharmacokinetic profiles of the novel COX-2 selective inhibitor cimicoxib in dogs.  

PubMed

Cimicoxib (CX) is a novel imidazole derivative that is a cyclo-oxygenase (COX)-2 selective non-steroidal anti-inflammatory drug and the latest COX-2 selective inhibitor to be released for veterinary use. Currently there is limited information available on the pharmacokinetic (PK) properties of CX. The aim of the current study was to evaluate the PK features of CX after administration of the recommended dose and after administration of a more variable dose rate in the form of the commercially available tablet. In addition, the effects of food intake on the PK properties were also evaluated. In the first study, five healthy Beagle dogs received 2mg/kg CX via the oral route following a period of fasting. The second study was conducted using six healthy Labrador retriever dogs which each received an 80 mg tablet (approximate dose 1.95-2.5mg/kg) using a crossover design, both in the fasted and fed condition. The plasma concentrations of CX were detected by a validated HPLC method. No adverse effects were observed in any dogs during the experiment. The results from the PK analysis were similar between the studies, regardless of precision of dose and fasted and fed conditions. The mean peak concentration of CX was 0.49 and 0.43 ?g/mL under fasted and fed conditions, respectively. The mean half-life was about 3h after all treatments. In addition, simulated multiple dosing data revealed that time over minimal effective concentration was similar after 1.95, 2.0 and 2.5mg/kg dose administrations. These findings suggest that slight variation from the recommended dose should not alter the therapeutic outcome. In addition, CX can be administered to fed dogs without significantly affecting blood levels. PMID:24461644

Kim, T W; Lebkowska-Wieruszewska, B; Owen, H; Yun, H I; Kowalski, C J; Giorgi, M

2014-04-01

10

Analysis of the effects of cyclooxygenase (COX)-1 and COX-2 in spinal nociceptive transmission using indomethacin, a non-selective COX inhibitor, and NS-398, a COX-2 selective inhibitor.  

PubMed

Prostaglandins are now thought to play an important role in nociceptive information transmission in the spinal cord. Prostaglandins are known to be produced by cyclooxygenase (COX), which catalyzes the conversion of arachidonic acid. Two forms of COX have been identified: COX-1, which is constitutively expressed in most tissues and organs, and COX-2, which is an inducible enzyme and is localized primarily in inflammatory cells and tissues. COX-2 mRNA has been reported to be expressed in the brain in normal rats. We investigated the role of COX-1 and COX-2 in the spinal nociceptive transmission during the rat formalin test and the hot plate test using indomethacin, a non-selective COX-1 and COX-2 inhibitor, and NS398, a selective COX-2 inhibitor. In the formalin test, drugs were administered intrathecally or intraperitoneally 10 min before (pre-treatment study) or 7 min after (post-treatment study) the formalin injection. Both intrathecally administered indomethacin and NS398 inhibited the formalin induced flinching behavior in a dose-dependent manner in the pre-treatment study, but not in the post-treatment study. Both indomethacin and NS398 had no effect on the hot plate test at a dose which depressed the formalin induced flinching behavior. These data suggested that COX-2 is expressed in the central nervous system, including the spinal cord, and that COX-2 plays an important role in the spinal nociceptive transmission during the formalin test, but not during the hot plate test. PMID:8955930

Yamamoto, T; Nozaki-Taguchi, N

1996-11-11

11

NSAID-induced enteropathy: are the currently available selective COX-2 inhibitors all the same?  

PubMed

Nonsteroidal anti-inflammatory drugs (NSAIDs) can induce intestinal mucosal damage, but the underlying mechanisms remain poorly understood. The present study investigated the effects of celecoxib, etoricoxib, indomethacin, and diclofenac on small bowel integrity in rats. Male rats were treated orally with test drugs for 14 days. Animals were processed for assessment of blood hemoglobin levels and hepatic mitochondrial functions, microscopic evaluation of small intestinal damage, Western blot analysis of cyclooxygenase-1 and -2 (COX-1, COX-2) expression, and assay of malondialdehyde (MDA), myeloperoxidase (MPO), and prostaglandin E2 (PGE2) levels in small intestine. Indomethacin and diclofenac decreased blood hemoglobin levels, whereas etoricoxib and celecoxib were without effects. Celecoxib caused a lower degree of intestinal damage in comparison with the other test drugs. Indomethacin and diclofenac, but not etoricoxib or celecoxib, reduced intestinal PGE2 levels. Test drugs did not modify intestinal COX-1 expression, although they enhanced COX-2, with the exception of celecoxib, which downregulated COX-2. Indomethacin, diclofenac, and etoricoxib altered mitochondrial respiratory parameters, although celecoxib was without effects. Indomethacin or diclofenac increased MDA and MPO levels in both jejunum and ileum. In the jejunum, etoricoxib or celecoxib did not modify such parameters, whereas in the ileum, etoricoxib, but not celecoxib, increased both MDA and MPO levels. These findings suggest that nonselective NSAIDs and etoricoxib can induce enteropathy through a topic action, whereas celecoxib lacks relevant detrimental actions. The selectivity profile of COX-1/COX-2 inhibition by test drugs and the related effects on prostaglandin production do not appear to play a major role in the pathogenesis of enteropathy. PMID:24135073

Fornai, Matteo; Antonioli, Luca; Colucci, Rocchina; Pellegrini, Carolina; Giustarini, Giulio; Testai, Lara; Martelli, Alma; Matarangasi, Antuela; Natale, Gianfranco; Calderone, Vincenzo; Tuccori, Marco; Scarpignato, Carmelo; Blandizzi, Corrado

2014-01-01

12

Structure-based pharmacophore of COX-2 selective inhibitors and identification of original lead compounds from 3D database searching method.  

PubMed

A four-point pharmacophore of COX-2 selective inhibitors was derived from a training set of 16 compounds, using the Catalyst program. It consists of a H bond acceptor, two hydrophobic groups and an aromatic ring, in accordance with SAR data of the compounds and with topology of the COX-2 active site. This hypothesis, combined with exclusion volume spheres representing important residues of the COX-2 binding site, was used to virtually screen the Maybridge database. Eight compounds were selected for an in vitro enzymatic assay. Five of them show COX-2 inhibition close to that of nimesulide and rofecoxib, two reference COX-2 selective inhibitors. As a result, structure-based pharmacophore generation was able to identify original lead compounds, inhibiting the COX-2 isoform. PMID:17030482

Michaux, Catherine; de Leval, Xavier; Julémont, Fabien; Dogné, Jean-Michel; Pirotte, Bernard; Durant, François

2006-12-01

13

Hybrid fluorescent conjugates of COX-2 inhibitors: search for a COX-2 isozyme imaging cancer biomarker.  

PubMed

The observation that the cyclooxygenase-2 (COX-2) isozyme is over-expressed in multiple types of cancer, relative to that in adjacent non-cancerous tissue, prompted this investigation to prepare a group of hybrid fluorescent conjugates wherein the COX inhibitors ibuprofen, (S)-naproxen, acetyl salicylic acid, a chlororofecoxib analog and celecoxib were coupled via a linker group to an acridone, dansyl or rhodamine B fluorophore. Within this group of compounds, the ibuprofen-acridone conjugate (10) showed potent and selective COX-2 inhibition (COX-2 IC(50)=0.67 ?M; SI=110.6), but its fluorescence emission (?(em)=417, 440 nm) was not suitable for fluorescent imaging of cancer cells that over-express the COX-2 isozyme. In comparison, the celecoxib-dansyl conjugate (25) showed a slightly lower COX-2 potency and selectivity (COX-2 IC(50)=1.1 ?M; SI>90) than the conjugate 10, and it possesses a better fluorescence emission (?(em)=500 nm). Ultimately, a celecoxib-rhodamine B conjugate (28) that exhibited moderate COX-2 potency and selectivity (COX-2 IC(50)=3.9 ?M; SI>25) having the best fluorescence emission (?(em)=580 nm) emerged as the most promising biomarker for fluorescence imaging using a colon cancer cell line that over-expresses the COX-2 isozyme. PMID:23200247

Bhardwaj, Atul; Kaur, Jatinder; Sharma, Sai Kiran; Huang, Zhangjian; Wuest, Frank; Knaus, Edward E

2013-01-01

14

COX-2 inhibitors as adjunctive therapy in schizophrenia.  

PubMed

Cyclooxygenase-2 (COX-2) is constitutively expressed in the central nervous system, and is thought to have an important functional role therein. COX-2 interacts with neurotransmitters such as acetylcholine, 5-hydroxytryptamine and glutamate but is also involved in the regulation of the central nervous system immune system and in inflammation via the effects of prostaglandins, in particular prostaglandin E2. A general therapeutic effect of the COX-2 inhibitor celecoxib on symptoms of schizophrenia was observed during a prospective, randomised, double-blind study of celecoxib add-on treatment to the atypical antipsychotic risperidone. The results from this trial of adjunctive therapy with a COX-2 inhibitor in schizophrenia are encouraging, and the findings support the view that an immunological/inflammatory process is involved in the pathogenesis of the disease. The add-on to an antipsychotic design of the study was chosen due to ethical reasons; in less acute schizophrenic states a monotherapy with COX-2 inhibitors would be interesting. From a theoretical point of view, other psychiatric indications for selective COX-2 inhibitors are discussed. COX-2 inhibitors have failed to show therapeutic effects in Alzheimer's disease but studies from basic research and a clinical perspective suggest it has an effect on disturbed cognition. In depression, however, signs of inflammation have been described for many years. Although results of clinical studies with COX-2 inhibitors in depression are still lacking, clinical improvement of a depressive syndrome has been observed in patients who have been treated with the COX-2 inhibitor rofecoxib due to other indications. These preliminary clinical data are encouraging for clinical therapeutic effects of the selective COX-2 inhibitors in psychiatric disorders, although these effects have to be confirmed in larger clinical studies. PMID:15268640

Müller, Norbert; Strassnig, Martin; Schwarz, Markus J; Ulmschneider, Markus; Riedel, Michael

2004-08-01

15

Effects of Nimesulide, a Selective COX-2 Inhibitor, on Cardiovascular Function in 2 Rat Models of Diabetes.  

PubMed

: 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. PMID:24621649

Leung, Joanne Y T; Pang, Catherine C Y

2014-07-01

16

Targeting KSHV/HHV-8 Latency with COX-2 Selective Inhibitor Nimesulide: A Potential Chemotherapeutic Modality for Primary Effusion Lymphoma  

PubMed Central

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-3?), 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.

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

2011-01-01

17

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

SciTech Connect

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.

Kang, Khong Bee [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore)]. E-mail: dmskkb@nccs.com.sg; Wang, Ting Ting [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore); Woon, Chow Thai [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore); Cheah, Elizabeth S. [Department of Pathology, Singapore General Hospital (Singapore); Moore, Xiao Lei [Baker Heart Research Institute, Melbourne (Australia); Zhu Congju [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore); Wong, Meng Cheong [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre (Singapore) and National Neuroscience Institute, Singapore General Hospital Campus (Singapore)

2007-03-01

18

COX-2 selective nonsteroidal anti-inflammatory drugs: current status.  

PubMed

Since, their introduction, COX (cyclooxygenase enzyme)-2 specific inhibitors have become a rapidly growing segment of the prescription drug market. Researchers have recently focused on the potentially lethal side effects associated with their. FDA has banned the use of nimesulide (hepatotoxic) in pediatric patients and rofecoxib (cardiovascular complications) in both adults and children. COX-2 inhibitors may decrease vascular prostacyclin production and may tip the balance in favour of prothrombotic eicosanoids (thromboxane A2) and lead to increased cardiovascular thrombotic events. COX-2 inhibitors can also result into increase blood pressure, macular eruptions, urticaria, pseudoporphyria, erythema multiforme, oedema, worsening of heart failure, fatal allergic vasculitis and aggravation of doxorubicin-mediated cardiac injury. The COX-2 enzyme is also involved in the development of many organ systems, and its inhibition may lead to various congenital defects in neonates. It has been reported that COX-2 inhibitors also interfere with implantation, hence their use should be avoided in sexually active women at risk of pregnancy. However, presently the choice of COX-2 selective inhibitors for a particular patient should be based upon their relative efficacy, toxicity, concomitant drug use, concurrent disease states, hepatic and renal function and relative cost. PMID:15926604

Mahajan, A; Sharma, Rashmi

2005-03-01

19

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

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.

Choi, Hyoung Chul [Department of Pharmacology and Aging-Associated Vascular Disease Research Center, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Kim, Hee Sun [Department of Microbiology and Aging-Associated Vascular Disease Research Center, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Lee, Kwang Youn [Department of Pharmacology and Aging-Associated Vascular Disease Research Center, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Chang, Ki Churl [Department of Pharmacology School of Medicine, and Institute of Health Sciences, Gyeongsang National University, Jinju 660-751 (Korea, Republic of)], E-mail: kcchang@gnu.kr; Kang, Young Jin [Department of Pharmacology and Aging-Associated Vascular Disease Research Center, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of)], E-mail: yjkang@med.yu.ac.kr

2008-11-28

20

Inhibition of haematogenous metastasis of colon cancer in mice by a selective COX2 inhibitor, JTE-522  

Microsoft Academic Search

It is proposed that non-steroidal anti-inflammatory drugs (NSAIDs) reduce colorectal tumorigenesis by inhibition of cyclooxygenase (COX). COX is a key enzyme in the conversion of arachidonic acid to prostaglandins and two isoforms of COX have been characterized, COX-1 and COX-2. Multiple studies have shown that COX-2 is expressed at high levels in colorectal tumours and play a role in colorectal

S Tomozawa; H Nagawa; N Tsuno; K Hatano; T Osada; J Kitayama; E Sunami; M E Nita; S Ishihara; H Yano; T Tsuruo; Y Shibata; T Muto

1999-01-01

21

Prevention of postoperative adhesion formation in rat uterine horn model by nimesulide: a selective COX2 inhibitor  

Microsoft Academic Search

BACKGROUND: Pelvic surgery is one of the main causes of intraperitoneal (i.p.) adhesions that create various medical problems including pelvic pain, bowel obstructions and female infertility. A rat model was used to investigate the efficacy of nimesulide, a selective cyclooxygenase-2 inhibitor, in the prevention of adhesion formation. METHODS: Fifty Wistar-Albino rats underwent bilateral uterine horn injury with a unipolar cautery.

T. Guvenal; A. Cetin; H. Ozdemir; O. Yanar; T. Kaya

2001-01-01

22

COX-2 inhibitors for the prevention of heterotopic ossification after THA.  

PubMed

Nonsteroidal anti-inflammatory drugs (NSAIDs) may prevent heterotopic ossification after total hip arthroplasty (THA). Cyclooxygenase 2 (COX-2) inhibitors may minimize side effects. The goal of this review was to compare the effectiveness and side effects of the perioperative use of selective COX-2 inhibitors with those of conventional NSAIDs in patients undergoing THA. We followed the systematic reviews' updated methods of the Cochrane Collaboration Back Review Group and searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials. We identified all randomized controlled trials until April 2009 enrolling THA patients and comparing COX-2 inhibitors to NSAIDs. We assessed their methodological quality and extracted data. Five randomized controlled trials were included. Prevention of heterotopic ossification and side effects with COX-2 inhibitors were significant in 2 studies. Discontinuation for side effects was not significant. COX-2 inhibitors do not prevent heterotopic ossification after THA significantly better than conventional NSAIDs, while they are advantageous regarding side effects. PMID:21661680

Vasileiadis, George I; Sioutis, Ioannis C; Mavrogenis, Andreas F; Vlasis, Konstantinos; Babis, George C; Papagelopoulos, Panayiotis J

2011-06-01

23

Synthesis, biological evaluation, and docking analysis of a novel family of 1-methyl-1H-pyrrole-2,5-diones as highly potent and selective cyclooxygenase-2 (COX-2) inhibitors.  

PubMed

As a continuous research for discovery of new COX-2 inhibitors, we present the simple chemical synthesis, in vitro biological screening, and molecular docking study of 1H-pyrrole-2,5-dione derivatives. New synthetic compounds were evaluated for the inhibitory activities on LPS-induced PGE2 production in RAW 264.7 macrophage cells as well as the COX-1 and COX-2 inhibitory potency. Among them, compound 9d (MPO-0029) was identified as more potent and selective COX-2 inhibitor [PGE2 IC50=8.7 nM, COX-2 IC50=6.0 nM; COX-2 selectivity index (SI)=>168] than celecoxib. Molecular docking experiments were further performed against COX-2 and COX-1 isozymes to determine their probable binding models. Results of molecular docking studies revealed that compound 9d (MPO-0029) has stronger binding interaction with COX-2 than with COX-1 isozyme, and provided successfully complementary theoretical support for the obtained experimental biological data. PMID:24656662

Kim, Kyung Ju; Choi, Min Ji; Shin, Ji-Sun; Kim, Minju; Choi, Hye-Eun; Kang, Seoung Mook; Jin, Jae Ho; Lee, Kyung-Tae; Lee, Jae Yeol

2014-04-15

24

Kinetics and docking studies of a COX-2 inhibitor isolated from Terminalia bellerica fruits.  

PubMed

Triphala is an Ayurvedic herbal formulation consisting of equal parts of three myrobalans: Terminalia chebula, Terminalia bellerica and Emblica officinalis. We recently reported that chebulagic acid (CA) isolated from Terminalia chebula is a potent COX-2/5-LOX dual inhibitor. In this study, compounds isolated from Terminalia bellerica were tested for inhibition against COX and 5-LOX. One of the fractionated compounds showed potent inhibition against COX enzymes with no inhibition against 5-LOX. It was identified as gallic acid (GA) by LC-MS, NMR and IR analyses. We report here the inhibitory effects of GA, with an IC(50) value of 74 nM against COX-2 and 1500 nM for COX-1, showing ?20 fold preference towards COX-2. Further docking studies revealed that GA binds in the active site of COX-2 at the non-steroidal anti-inflammatory drug (NSAID) binding site. The carboxylate moiety of GA interacts with Arg120 and Glu524. Based on substrate dependent kinetics, GA was found to be a competitive inhibitor of both COX-1 and COX-2, with more affinity towards COX-2. Taken together, our studies indicate that GA is a selective inhibitor of COX-2. Being a small natural product with selective and reversible inhibition of COX-2, GA would form a lead molecule for developing potent anti-inflammatory drug candidates. PMID:20441561

Reddy, Tamatam Chandramohan; Aparoy, Polamarasetty; Babu, Neela Kishore; Kumar, Kotha Anil; Kalangi, Suresh Kumar; Reddanna, Pallu

2010-10-01

25

COX-2 inhibitor reduces skeletal muscle hypertrophy in mice  

PubMed Central

Anti-inflammatory strategies are often used to reduce muscle pain and soreness that can result from high-intensity muscular activity. However, studies indicate that components of the acute inflammatory response may be required for muscle repair and growth. The hypothesis of this study was that cyclooxygenase (COX)-2 activity is required for compensatory hypertrophy of skeletal muscle. We used the synergist ablation model of skeletal muscle hypertrophy, along with the specific COX-2 inhibitor NS-398, to investigate the role of COX-2 in overload-induced muscle growth in mice. COX-2 was expressed in plantaris muscles during compensatory hypertrophy and was localized mainly in or near muscle cell nuclei. Treatment with NS-398 blunted the increases in mass and protein content in overloaded muscles compared with vehicle-treated controls. Additionally, the COX-2 inhibitor decreased activity of the urokinase type plasminogen activator, macrophage accumulation, and cell proliferation, all of which are required for hypertrophy after synergist ablation. Expression of insulin-like growth factor-1 and phosphorylation of Akt, mammalian target of rapamycin, and p70S6K were increased following synergist ablation, but were not affected by NS-398. Additionally, expression of atrogin-1 was reduced during hypertrophy, but was also not affected by NS-398. These results demonstrate that COX-2 activity is required for skeletal muscle hypertrophy, possibly through facilitation of extracellular protease activity, macrophage accumulation, and cell proliferation.

Novak, Margaret L; Billich, William; Smith, Sierra M.; Sukhija, Kunal B.; McLoughlin, Thomas J.; Hornberger, Troy A.; Koh, Timothy J.

2009-01-01

26

Clinical effects of COX-2 inhibitors on cognition in schizophrenia.  

PubMed

An activation of pro-inflammatory cytokines in the central nervous system is associated with cognitive disturbances. This process is mediated by prostaglandins and cyclo-oxygenase-2 (COX-2). COX-2 inhibitors have been suggested to show beneficial effects in disorders associated with cognitive disturbance, although clinical effects on cognition have not been shown until today. Data from a schizophrenia study were reevaluated under the aspect whether an effect on the positive and negative syndrome scale (PANSS) factor cognition can be observed during therapy with the COX-2 inhibitor celecoxib add on to risperidone in comparison to riperidone alone. Beside the effect on the PANSS total score, the effect on the cognition factor was the most pronounced using the analysis of covariance compared to all other factors of the PANSS (p < 0.06). Although suggestions of basic research led to an expected therapeutic effect of COX-2 inhibitors on cognition, this effect could not yet be shown clinically. In schizophrenia, the effect on cognition contributes to the therapeutic effect of COX-2 inhibitors. PMID:15549344

Müller, Norbert; Riedel, Michael; Schwarz, Markus J; Engel, Rolf R

2005-04-01

27

COX-2 inhibitors celecoxib and parecoxib: valuable options for postoperative pain management.  

PubMed

COX-2 inhibitors are equally as efficacious as the non-selective NSAIDs for the treatment of postoperative pain, but have the advantages of a better gastrointestinal side-effect profile as well as a lack of antiplatelet effects. There have been recent concerns regarding the cardiovascular side effects of COX-2 inhibitors. Nonetheless, they remain a valuable option for postoperative pain management. The pharmacology of these agents and available studies are reviewed. PMID:17305567

Gajraj, Noor M

2007-01-01

28

Selective COX2 Inhibition Improves Endothelial Function in Coronary Artery Disease  

Microsoft Academic Search

Background—There is an ongoing debate as to whether the gastrointestinal safety of COX-2 inhibition compared with nonsteroidal antiinflammatory drugs (NSAIDs) may come at the cost of increased cardiovascular events. In view of the large number of patients at cardiovascular risk requiring chronic analgesic therapy with COX-2 inhibitors for arthritic and other inflammatory conditions, the effects of selective COX-2 inhibition on

Rémy Chenevard; David Hürlimann; Markus Béchir; Frank Enseleit; Lukas Spieker; Matthias Hermann; Walter Riesen; Steffen Gay; Renate E. Gay; Michel Neidhart; Beat Michel; Thomas F. Lüscher; Georg Noll; Frank Ruschitzka

2009-01-01

29

A COX-2 inhibitor nimesulide analog selectively induces apoptosis in Her2 overexpressing breast cancer cells via cytochrome c dependent mechanisms  

PubMed Central

Epidemiological and animal model studies have suggested that non-steroidal anti-inflammatory drugs (NSAIDs) can act as chemopreventive agents. The cyclooxygenase-2 (COX-2) inhibitor nimesulide shows anti-cancer effect in different type of cancers. In the current study, five breast carcinoma cell lines were used to explore the anti-cancer mechanisms of a nimesulide derivative compound 76. The compound dose dependently suppressed SKBR-3, BT474 and MDA-MB-453 breast cancer cell proliferation with IC50 of 0.9 ?M, 2.2 ?M and 4.0 ?M, respectively. However, it needs much higher concentrations to inhibit MCF-7 and MDA-MB-231 breast cancer cell growth with IC50 at 22.1 ?M and 19.6 ?M, respectively. Further investigation reveals that compound 76 induced apoptosis in SKBR-3 and BT474 cells. Since these cells are Her2 overexpressing cells, the Her2 intracellular signaling pathways were examined after the treatment. There was no significant changing of kinase activity. However, the cytochrome c release assay indicated that the apoptosis induced by the compound was mediated by the mitochondria. These results suggest that compound 76 selectively induce apoptosis in Her2 overexpressing breast cancer cells through the mitochondria, and could be used as a lead to design more potent derivatives.

Chen, Bin; Su, Bin; Chen, Shiuan

2010-01-01

30

Evaluation of an Aerosolized Selective COX-2 Inhibitor as a Potentiator of Doxorubicin in a Non-Small-Cell Lung Cancer Cell Line  

PubMed Central

Purpose To evaluate the in vitro effects of an aerosolized cyclooxygenase-2 (COX-2) inhibitor, nimesulide, on the cytotoxicity and apoptotic response of doxorubicin against the human lung adenocarcinoma cell line A549. Methods Nimesulide was formulated into a metered dose inhaler (MDI) formulation and characterized for aerodynamic particle size and medication delivery. The in vitro cytotoxicity of nimesulide-MDI in the presence or absence of doxorubicin was assessed by using the six-stage viable impactor by an already standardized method. Induction of apoptosis in A549 cells by nimesulide (nonaerosolized or aerosolized) in combination with doxorubicin was evaluated by established techniques such as caspase-3 estimation and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining. Finally, to understand the mechanism of action, the influence of different treatments on the expression of COX-2 and peroxisome proliferator-activated receptor-? (PPAR-?) in A549 cells was studied by immunoblotting. Results The nimesulide-MDI formulation had a mass median aerodynamic diameter (MMAD) of 1.1 ?m, (GSD = 2.8) and a medication delivery of 51 ?g/shot. Nimesulide-MDI (40 shots) in combination with doxorubicin (0.01 ?g/ml) had a cell kill of more than 60% as determined by in vitro cytotoxicity assay. The specific caspase-3 activity in A549 cells treated with nimesulide (40 ?g/ml) and doxorubicin (0.25 ?g/ml) in combination was 3 and 5 times higher than doxorubicin and nimesulide, respectively. Further, TUNEL staining showed apoptosis in over 30% of A549 cells treated with aerosolized nimesulide and doxorubicin combination vs. negligible as seen in cells treated individually. The expression of COX-2 was not altered in control or treatments, whereas PPAR-? was expressed only in the combination treatment. Conclusion Our results indicate that aerosolized nimesulide significantly enhances doxorubicin activity against A549 cells, and the enhanced cytotoxicity was probably mediated via a COX-2–independent mechanism.

Haynes, Alfred; Shaik, Madhu Sudhan; Chatterjee, Abhijit; Singh, M.

2010-01-01

31

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

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 ?M 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. PMID:24780593

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

2014-06-10

32

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

PubMed Central

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.

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

2011-01-01

33

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

PubMed

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

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

2011-01-01

34

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

PubMed

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)-l?] 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-1? 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. PMID:21268133

Kaur, Jasmeet; Sanyal, S N

2011-09-01

35

COX-2 inhibitors as antidepressants and antipsychotics: clinical evidence.  

PubMed

Antidepressant and antipsychotic drugs, predominantly serotonin and/or norepinephrine reuptake inhibitors and dopamine D2-antagonizing antipsychotic compounds, have several limitations. In addition, the exact pathophysiological mechanism leading to serotonergic, noradrenergic and dopaminergic dysfunction in psychotic disorders remains unclear. It has been postulated that an inflammatory mechanism may be involved in the pathogenesis of both depression and psychotic disorders. Furthermore, the differential activation of the enzyme indoleamine 2,3-dioxygenase (IDO) and of the tryptophan/kynurenine metabolic pathway, resulting in the increased production of kynurenic acid in schizophrenia, and a possible increase in quinolinic acid in depression, also may play a key role in these diseases. Such differences are associated with an imbalance in glutamatergic neurotransmission that may contribute to increased levels of NMDA agonism in depression and NMDA antagonism in schizophrenia. In addition, immunological imbalance results in the increased production of PGE2 in schizophrenia and depression, as well as increased COX-2 expression in schizophrenia. Although there is evidence supporting the hypothesis that interactions between immune system components, IDO, the serotonergic system and glutamatergic neurotransmission play a key role in schizophrenia and depression, several gaps in knowledge remain, such as regarding the role of genetics, disease course, gender and different psychopathological states. There is evidence indicating that anti-inflammatory therapy may have beneficial effects in schizophrenia and major depression (MD). COX-2 inhibitors have been tested in animal models and in preliminary clinical trials, demonstrating favorable activity compared with placebo, both in schizophrenia and MD. However, the effects of COX-2 inhibition in the CNS, as well as toward different components of the inflammatory system, kynurenine metabolism and glutamatergic neurotransmission, require further evaluation, which should include clinical trials with larger numbers of patients. The potential inflammatory mechanism in schizophrenia and MD, and the possible therapeutic advantages of targeting this mechanism in the treatment of these disorders is discussed in this review. PMID:20047157

Müller, Norbert

2010-01-01

36

Psychotropic effects of COX-2 inhibitors--a possible new approach for the treatment of psychiatric disorders.  

PubMed

Cyclooxygenase-2 (COX-2)--constitutively expressed in the CNS--is suggested to have an important functional role in the CNS. COX-2 interacts with neurotransmitters such as acetylcholine, serotonin, and glutamate, but is also involved in the regulation of immune system and in inflammation in the central nervous system (CNS) via effects of prostaglandins, in particular prostaglandin E (2). Recently, a role for the new generation of selective COX-2 inhibitors in the treatment of psychiatric disorders is discussed. Until now, COX-2 inhibitors have failed to show therapeutic effects in Alzheimer's disease, but studies from basic research point to a possible effect on cognition. A clinical effect of the COX-2 inhibitor celecoxib on cognition was observed in schizophrenic patients. The therapeutic effect of celecoxib add-on treatment to the atypical antipsychotic risperidone, however, is not restricted to cognition. A general effect on symptoms of schizophrenia was observed, which supports the view that an immunological/inflammatory process is involved in the pathogenesis of schizophrenia. In depression, however, signs of inflammation have been described since many years. Although results of clinical studies with COX-2 inhibitors in depression are still lacking, clinical improvement of a depressive syndrome has been observed in patients, who have been treated with rofecoxib due to other indications. These preliminary clinical data are encouraging for therapeutic effects of the selective COX-2 inhibitors in psychiatric disorders, although these effects have to be confirmed in bigger clinical studies. PMID:15551192

Müller, N; Riedel, M; Schwarz, M J

2004-11-01

37

The pyrrole moiety as a template for COX-1/COX-2 inhibitors.  

PubMed

Aroyl- and thiophene-substituted pyrrole derivatives have been synthesized as a new class of COX-1/COX-2 inhibitors. The inhibition of COX-1 was evaluated in a biological system using bovine PMNLs as the enzyme source, whereas LPS-stimulated human monocytes served as the enzyme source for inducible COX-2. The determination of the concentration of arachidonic acid metabolites was performed by HPLC for COX-1 and RIA for COX-2. Variation of the substitution pattern led to a series of active compounds which showed inhibition for COX-1 and COX-2. Structural requirements for the development of COX-1/COX-2 inhibitors are discussed. PMID:10889329

Dannhardt, G; Kiefer, W; Krämer, G; Maehrlein, S; Nowe, U; Fiebich, B

2000-05-01

38

The Anti-Cancer Effect of COX2 Inhibitors on Gastric Cancer Cells  

Microsoft Academic Search

Epidemiologic studies have shown that nonsteroidal anti-inflammatory drugs could reduce the risk of cancer development including\\u000a gastric cancer. This study was performed to identify the antineoplastic mechanism in gastric cancer cells affected by celecoxib,\\u000a a selective COX-2 inhibitor. MTT assay, ELISA for prostaglandin E2 (PGE2), cell-cycle analyses, immunofluorescent staining, and flow cytometry were performed after treating human gastric cancer\\u000a cell

Soo-Jeong Cho; Nayoung Kim; Joo Sung Kim; Hyun Chae Jung; In Sung Song

2007-01-01

39

Dual effects of nimesulide, a COX2 inhibitor, in human platelets  

Microsoft Academic Search

Nimesulide (CAS 51803-78-2) has been shown to exert marked anti-inflammatroy effect in several in vivo models of inflammation. Since nimesulide is considered to be a selective inhibitor of COX-2, it has not been studied in detail in relation to its mechanistic effects on platelets, which express COX-1. This study was conducted to investigate the effects of nimesulide in platelet aggregation.

Sheikh A. Saeed; M. N. Afzal; Bukhtiar H. Shah

1998-01-01

40

Oral bioavailability and pharmacokinetics of DRF4367, a new cox-2 inhibitor in rats  

Microsoft Academic Search

Summary  The pharmacokinetic characterization of DRF-4367 (a new diaryl pyrazole derivative), a potent selective COX-2 inhibitor was\\u000a performed in Wistar rats. In the first study, a single dose of 2, 5, 10, 30 or 100 mg\\/kg DRF-4367 was given orally to rats\\u000a for investigating the dose proportionality and\\/or linearity in the pharmacokinetics. In the second study, a single intravenous\\u000a bolus dose

Mullangi Ramesh; Rao N. V. S. Mamidi; Kota Jagannath; Sunil Kumar Singh; Kalleda Srinivasa Rao; Yeleswarapu Koteswar Rao; Casturi Seshagirirao; Ramanujam Rajagopalan; Nuggehallyr Srinivas

2003-01-01

41

Discovery of a potent, selective and orally active canine COX2 inhibitor, 2-(3-difluoromethyl-5-phenyl-pyrazol-1-yl)-5-methanesulfonyl-pyridine  

Microsoft Academic Search

Structure–activity relationship (SAR) studies of 2-[3-di(and tri)fluoromethyl-5-arylpyrazol-1-yl]-5-methanesulfonylpyridine derivatives for canine COX enzymes are described. This led to the identification of 12a as a lead candidate for further progression. The in vitro and in vivo activity of 12a for the canine COX-2 enzyme as well as its in vivo efficacy and pharmacokinetic properties in dog are highlighted.

Jin Li; Kristin M. Lundy DeMello; Henry Cheng; Subas M. Sakya; Brian S. Bronk; Robert J. Rafka; Burton H. Jaynes; Carl B. Ziegler; Carolyn Kilroy; Donald W. Mann; Eric L. Nimz; Michael P. Lynch; Michelle L. Haven; Nicole L. Kolosko; Martha L. Minich; Chao Li; Jason K. Dutra; Bryson Rast; Rhonda M. Crosson; Barry J. Morton; Glen W. Kirk; Kathleen M. Callaghan; David A. Koss; Andrei Shavnya; Lisa A. Lund; Scott B. Seibel; Carol F. Petras; Annette Silvia

2004-01-01

42

Selective inhibition of COX2 in humans is associated with less gastrointestinal injury: a comparison of nimesulide and naproxen  

Microsoft Academic Search

BACKGROUNDSelective inhibitors of cyclooxygenase (COX)-2 may provoke less gastric damage and platelet inhibition than conventional non-steroidal anti-inflammatory drugs.AIMSWe compared the biochemical and gastrointestinal effects of nimesulide, a potent and selective COX-2 inhibitor, with naproxen which exhibits no selectivity.SUBJECTSThirty six healthy volunteers were randomised to nimesulide 100 mg or naproxen 500 mg twice daily for two weeks in a double blind,

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

2001-01-01

43

Etoricoxib: new drug. Avoid using cox-2 inhibitors for pain.  

PubMed

(1) Paracetamol is the first-choice analgesic for joint pain. Nonsteroidal antiinflammatory drugs (NSAIDs), especially ibuprofen, are second-line options. Cox-2 inhibitors are no more effective than traditional NSAIDs and have no tangible advantages in terms of gastrointestinal tolerability. In contrast, they expose patients to an increased risk of cardiovascular adverse effects. (2) Etoricoxib is marketed in some European countries to relieve symptoms of osteoarthritis, rheumatoid arthritis, and gout attacks. (3) Many clinical trials have tested etoricoxib in these indications, as well as in ankylosing spondylitis, low back pain, and various types of acute pain. Etoricoxib was no more effective than other NSAIDs such as ibuprofen, naproxen or diclofenac in these situations. (4) Comparative trials showed a higher overall mortality rate with etoricoxib than with naproxen. A combined analysis of long-term comparative trials including 5441 patients, mainly versus naproxen, showed that etoricoxib does not reduce the risk of perforation, ulcer or severe gastrointestinal haemorrhage. Similarly, it does not reduce the risk of mild gastrointestinal events in at-risk patients: those with a history of gastrointestinal disorders, aspirin use, etc. (5) Three trials including a total of 34 701 patients (MEDAL programme) compared cardiovascular thrombotic events associated with etoricoxib and diclofenac. Overall, the cardiovascular risks appear to be similar but the thrombotic risk may be slightly higher with diclofenac than with other conventional NSAIDs. (6) Etoricoxib provoked arterial hypertension, oedema and heart failure during clinical trials. Serious skin reactions were reported both during clinical trials and after marketing, but their precise incidence is not known. Etoricoxib is partly metabolised by the cytochrome P450 isoenzyme CYP 3A4 and increases the bioavailability of ethinylestradiol. (7) When a NSAID is considered, drugs with which we have the most experience should be chosen, such as ibuprofen, and used at the lowest acceptable dose regimen (daily dose and length of treatment). Etoricoxib should be avoided. PMID:18084859

2007-12-01

44

Cellular and molecular studies of the effects of a selective COX-2 inhibitor celecoxib in the cardiac cell line H9c2 and their correlation with death mechanisms.  

PubMed

Cardiovascular disease is one of the leading causes of death worldwide, and evidence indicates a correlation between the inflammatory process and cardiac dysfunction. Selective inhibitors of cyclooxygenase-2 (COX-2) enzyme are not recommended for long-term use because of potentially severe side effects to the heart. Considering this and the frequent prescribing of commercial celecoxib, the present study analyzed cellular and molecular effects of 1 and 10 µM celecoxib in a cell culture model. After a 24-h incubation, celecoxib reduced cell viability in a dose-dependent manner as also demonstrated in MTT assays. Furthermore, reverse transcription-polymerase chain reaction analysis showed that the drug modulated the expression level of genes related to death pathways, and Western blot analyses demonstrated a modulatory effect of the drug on COX-2 protein levels in cardiac cells. In addition, the results demonstrated a downregulation of prostaglandin E2 production by the cardiac cells incubated with celecoxib, in a dose-specific manner. These results are consistent with the decrease in cell viability and the presence of necrotic processes shown by Fourier transform infrared analysis, suggesting a direct correlation of prostanoids in cellular homeostasis and survival. PMID:24519091

Sakane, K K; Monteiro, C J; Silva, W; Silva, A R; Santos, P M; Lima, K F; Moraes, K C M

2014-01-01

45

Cellular and molecular studies of the effects of a selective COX-2 inhibitor celecoxib in the cardiac cell line H9c2 and their correlation with death mechanisms  

PubMed Central

Cardiovascular disease is one of the leading causes of death worldwide, and evidence indicates a correlation between the inflammatory process and cardiac dysfunction. Selective inhibitors of cyclooxygenase-2 (COX-2) enzyme are not recommended for long-term use because of potentially severe side effects to the heart. Considering this and the frequent prescribing of commercial celecoxib, the present study analyzed cellular and molecular effects of 1 and 10 µM celecoxib in a cell culture model. After a 24-h incubation, celecoxib reduced cell viability in a dose-dependent manner as also demonstrated in MTT assays. Furthermore, reverse transcription-polymerase chain reaction analysis showed that the drug modulated the expression level of genes related to death pathways, and Western blot analyses demonstrated a modulatory effect of the drug on COX-2 protein levels in cardiac cells. In addition, the results demonstrated a downregulation of prostaglandin E2 production by the cardiac cells incubated with celecoxib, in a dose-specific manner. These results are consistent with the decrease in cell viability and the presence of necrotic processes shown by Fourier transform infrared analysis, suggesting a direct correlation of prostanoids in cellular homeostasis and survival.

Sakane, K.K.; Monteiro, C.J.; Silva, W.; Silva, A.R.; Santos, P.M.; Lima, K.F.; Moraes, K.C.M.

2014-01-01

46

Identification and optimisation of a novel series of pyrimidine based cyclooxygenase-2 (COX2) inhibitors. Utilisation of a biotransformation approach  

Microsoft Academic Search

Many years of work have been invested in the identification of potent and selective COX-2 inhibitors for the treatment of chronic inflammatory pain. One issue faced by workers is the balance between the lipophilicity required for potent enzyme inhibition and the physical properties necessary for drug absorption and distribution in vivo. Frequently approaches to reduce lipophilicity through introduction of polar

Paul J. Beswick; Andrew P. Blackaby; Chas Bountra; Terry Brown; Kerry Browning; Ian B. Campbell; John Corfield; Robert J. Gleave; Steve B. Guntrip; Richard M. Hall; Sean Hindley; Paul F. Lambeth; Fiona Lucas; Neil Mathews; Alan Naylor; Hazel Player; Helen S. Price; Phillip J. Sidebottom; Nicholas L. Taylor; Graham Webb; Joanne Wiseman

2009-01-01

47

The COX-2 inhibitors, meloxicam and nimesulide, suppress neurogenesis in the adult mouse brain  

PubMed Central

Background and purpose: In adults, neurogenesis persists in the hippocampus and the subventricular zone (SVZ), and this is important for learning and memory. Inhibitors of COX-2 suppress ischaemia-induced neurogenesis in the hippocampus. Here, we have determined the effects of COX-2 inhibitors on neurogenesis throughout the normal adult mouse brain. Experimental approach: Young adult mice were treated with COX-2 inhibitors, and the proliferation of neural progenitor cells was measured in the SVZ and hippocampus. In addition, the local uptake of lentiviral vectors in the rostral migratory stream enabled the formation of new neurons in the olfactory bulb (OB) to be assessed. Key results: The COX-2 inhibitor meloxicam suppressed progenitor cell proliferation in the SVZ and hippocampus. A significant decrease in the appearance of new neurons in the OB was also observed. Similar effects on progenitor proliferation in the SVZ were seen with nimesulide. The absence of COX-2 expression in the proliferating progenitors in vivo, and the lack of effect of the COX-2 inhibitors on the growth rate of a cultured progenitor cell line, suggest that the effect is indirect. The specific expression of COX-2 in resting microglia that closely associate with the proliferating progenitor cells provides for a possible site of action. Conclusions and implications: Treatment with a COX-2 inhibitor results in a substantial inhibition of adult neurogenesis. Studies on human tissues are warranted in order to determine if this effect extends to humans, and whether inhibition of neurogenesis should be considered as an adverse effect of these drugs.

Goncalves, Maria Beatriz; Williams, Emma-Jane; Yip, Ping; Yanez-Munoz, Rafael J; Williams, Gareth; Doherty, Patrick

2010-01-01

48

Reduced risk of human lung cancer by selective cyclooxygenase 2 (COX-2) blockade: results of a case control study.  

PubMed

We conducted a case control study of selective cyclooxygenase-2 (COX-2) blocking agents and lung cancer. A total of 492 newly diagnosed lung cancer cases were ascertained during January 1, 2002 to September 30, 2004, at The Ohio State University Medical Center, Columbus, Ohio. All cases were confirmed by examination of the pathology report. Healthy population controls without cancer were ascertained during the same time period. Controls were frequency matched at a rate of 2:1 to the cases by age, gender, and county of residence. We collected information on type, frequency, and duration of use of selective COX-2 inhibitors (primarily celecoxib or rofecoxib) and nonselective NSAIDs such as ibuprofen and aspirin. Estimates of odds ratios (OR) were obtained with adjustment for cigarette smoking, age and other potential confounders using logistic regression analysis. Odds Ratios for selective COX-2 inhibitors were adjusted for past use of other NSAIDs. Use of any selective COX-2 inhibitor for more than one year produced a significant (60%) reduction in the risk of lung cancer (OR=0.40, 95% CI=0.19-0.81). Observed risk reductions were consistent for men (OR=0.26, 95% CI=0.10-0.62) and women (OR=0.52, 95% CI=0.24-1.13) and for individual COX-2 inhibitors (OR=0.28, 95% CI=-0.12-0.67, for celecoxib and OR=0.55, 95% CI=0.19-1.56, for rofecoxib). Intake of ibuprofen or aspirin also produced significant risk reductions (OR=0.40, 95% CI=0.23-0.73 and OR=0.53, 95% CI=0.34-0.82, respectively), whereas acetaminophen, an analgesic with negligible COX-2 activity, had no effect on the risk (OR=1.36, 95% CI=0.53-3.37). This investigation demonstrates for the first time that selective COX-2 blocking agents have strong potential for the chemoprevention of human lung cancer. PMID:17589567

Harris, Randall E; Beebe-Donk, Joanne; Alshafie, Galal A

2007-01-01

49

Association between COX-2 Expression and Effectiveness of COX-2 Inhibitors in Phase II Trial in Patients with Metastatic Colorectal Adenocarcinoma  

PubMed Central

Aim The role for the cyclooxygenase-2 (COX-2) pathway in colorectal carcinogenesis has been suggested in pre-clinical models. In a previously reported phase II trial, the addition of COX-2 inhibitor celecoxib to irinotecan and capecitabine did not appear to significantly increase the activity of chemotherapy in patients with metastatic colorectal carcinoma (mCRC). We evaluated COX-2 expression in the available tumors from patients enrolled by immunohistochemistry and its correlation with clinical outcome. Patients and Methods Fifty-one patients with mCRC were enrolled in the phase II study between June 2002 and November 2005. Patients received a combination of irinotecan 70 mg/m2 over 30 min i.v. on days 1 and 8, capecitabine 1,000 mg/m2 twice per day orally on days 1-14 and the COX-2 inhibitor celecoxib at a daily dose of 800 mg continuously. Cycles were repeated every 21 days. Formalin-fixed paraffin-embedded tumor tissue samples were available for 17 patients enrolled on that study. COX-2 expression was evaluated by immunohistochemistry and correlated with clinical outcome. Results In the phase II study, the objective response rate was 41%. The median time to progression was 7.7 months and median survival time was 21.2 months. Tumor COX-2 expression by immunohistochemistry was assessed for 17 patients enrolled in that same phase II study. While not statistically significant, the response rate was better for patients in the low COX-2 expression group, while time to progression and overall survival was longer in patients in the high COX-2 expression group. This discrepancy can be partially attributed to the small sample size. Conclusion In the previously published phase II study, the addition of celecoxib to irinotecan and capecitabine did not appear to significantly increase the activity of chemotherapy. COX-2 expression by immunohistochemistry was neither prognostic nor predictive for response.

Almhanna, Khaldoun; El-Rayes, Bassel; Sethi, Seema; Dyson, Gregory; Heilbrun, Lance; Philip, Philip A; Sarkar, Fazlul

2013-01-01

50

Overcoming paclitaxel resistance in uterine endometrial cancer using a COX-2 inhibitor.  

PubMed

Cyclooxygenase (COX)-2 inhibitors have been reported to potentially modulate the resistance of cancer cells to chemotherapeutic drugs by affecting multidrug resistance 1 (MDR1) expression. In the present study, we investigated the association between COX-2 and MDR1 expression in endometrial cancers and evaluated the effects of the COX-2 inhibitor, etodolac, in combination with paclitaxel on paclitaxel-resistant endometrial cancer cells. The relationship between COX-2 and MDR1 mRNA expression was examined by quantitative PCR in 36 endometrial cancer specimens. The paclitaxel-resistant cell line OMC-2P was established from OMC-2 cells. Paclitaxel (1 µg/ml) with or without etodolac (10 µg/ml) was added to OMC-2 and OMC-2P cells, and COX-2 and MDR1 mRNA expression levels were examined. The concentration of prostaglandin E2 (PGE2) in the supernatant of each cell line was examined by enzyme-linked immunosorbent assay. The function of MDR1 was determined by intracellular accumulation of rhodamine 123 using flow cytometry, and the concentration of intracellular paclitaxel was determined by high-performance liquid chromatography. We found a positive relationship between COX-2 and MDR1 mRNA expression in endometrial cancer. Both COX-2 mRNA expression and PGE2 production were elevated in resistant OMC-2P cells when compared to non-resistant OMC-2 cells. Additionally, MDR1 mRNA expression was markedly upregulated in OMC-2P cells. In OMC-2 cells, COX-2 and MDR1 mRNA levels were significantly upregulated by paclitaxel treatment and downregulated by co-administration with etodolac. In OMC-2P cells, COX-2 mRNA expression was also significantly upregulated by paclitaxel treatment and tended to be downregulated by co-administration with etodolac. Moreover, co-administration of paclitaxel and etodolac suppressed the induction of MDR1 mRNA. Rhodamine 123 efflux was increased in OMC-2P cells when compared to the efflux in the OMC-2 cells and was increased in response to paclitaxel treatment. Co-administration of paclitaxel and etodolac in both cell lines resulted in decreased rhodamine 123 efflux. The actual concentration of intracellular paclitaxel in OMC-2P cells was significantly lower than that in OMC-2 cells treated with paclitaxel alone and was significantly increased after co-administration of paclitaxel and etodolac. These findings suggest that paclitaxel resistance may be associated with COX-2 and MDR1 expression in cancer cells. Co-administration of COX-2 inhibitors and paclitaxel may have a key role in modulating or overcoming paclitaxel resistance in endometrial cancers. PMID:24100466

Hasegawa, Kiyoshi; Ishikawa, Kunimi; Kawai, Satoshi; Torii, Yutaka; Kawamura, Kyoko; Kato, Rina; Tsukada, Kazuhiko; Udagawa, Yasuhiro

2013-12-01

51

Antiinflammatory and neuroprotective actions of COX2 inhibitors in the injured brain  

PubMed Central

Overexpression of COX2 appears to be both a marker and an effector of neural damage after a variety of acquired brain injuries, and in natural or pathological aging of the brain. COX2 inhibitors may be neuroprotective in the brain by reducing prostanoid and free radical synthesis, or by directing arachidonic acid down alternate metabolic pathways. The arachidonic acid shunting hypothesis proposes that COX2 inhibitors' neuroprotective effects may be mediated by increased formation of potentially beneficial eicosanoids. Under conditions where COX2 activity is inhibited, arachidonic acid accumulates or is converted to eicosanoids via lipoxygenases and cytochrome P450 (CYP) epoxygenases. Several P450 eicosanoids have been demonstrated to have beneficial effects in the brain and/or periphery. We suspect that arachidonic acid shunting may be as important to functional recovery after brain injuries as altered prostanoid formation per se. Thus, COX2 inhibition and arachidonic acid shunting have therapeutic implications beyond the suppression of prostaglandin synthesis and free radical formation.

Strauss, Kenneth I.

2008-01-01

52

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

National Technical Information Service (NTIS)

The objective of this study was to determine in a controlled chemoprevention trial the ability of a COX-2 inhibitor to inhibit the development of spontaneously arising genital tract adenocarcinoma in the laying hen (Gall us Domesticus) animal model of ova...

M. N. Barnes

2007-01-01

53

Combination of EGFR and COX-2 inhibitors in breast cancer patient.  

PubMed

Ther combination of EGFR and COX-2 inhibitors in breast cancer patient treatment is a topic of interest. In this work, the author discusses on the synergistic effect of concomitant usage of the two drugs and also further notes on the myth in using this combination. PMID:22362382

Wiwanitkit, Viroj

2012-08-01

54

Inhibition of 11?-hydroxysteroid dehydrogenase type II selectively blocks the tumor COX-2 pathway and suppresses colon carcinogenesis in mice and humans  

PubMed Central

Colorectal cancer (CRC) is a leading cause of cancer death, yet primary prevention remains the best approach to reducing overall morbidity and mortality. Studies have shown that COX-2–derived PGE2 promotes CRC progression, and both nonselective COX inhibitors (NSAIDs) and selective COX-2 inhibitors (such as glucocorticoids) reduce the number and size of colonic adenomas. However, increased gastrointestinal side effects of NSAIDs and increased cardiovascular risks of selective COX-2 inhibitors limit their use in chemoprevention of CRC. We found that expression of 11?–hydroxysteroid dehydrogenase type II (11?HSD2), which converts active glucocorticoids to inactive keto-forms, increased in human colonic and Apc+/min mouse intestinal adenomas and correlated with increased COX-2 expression and activity. Furthermore, pharmacologic inhibition or gene silencing of 11?HSD2 inhibited COX-2–mediated PGE2 production in tumors and prevented adenoma formation, tumor growth, and metastasis in mice. Inhibition of 11?HSD2 did not reduce systemic prostacyclin production or accelerate atherosclerosis in mice, thereby avoiding the major cardiovascular side effects seen with systemic COX-2 inhibitors. Therefore, 11?HSD2 inhibition represents what we believe to be a novel approach for CRC chemoprevention and therapy by increasing tumor glucocorticoid activity, which in turn selectively blocks local COX-2 activity.

Zhang, Ming-Zhi; Xu, Jie; Yao, Bing; Yin, Huiyong; Cai, Qiuyin; Shrubsole, Martha J.; Chen, Xiwu; Kon, Valentina; Zheng, Wei; Pozzi, Ambra; Harris, Raymond C.

2009-01-01

55

COX-2 inhibitor nimesulide analogs are aromatase suppressors in breast cancer cells  

PubMed Central

Cyclooxygenase-2 (COX-2) inhibitor nimesulide derivatives compound A and B decreased aromatase activity in breast cancer cells via a novel mechanism different to aromatase inhibitors (AIs), and were defined as “aromatase suppressors”. Breast carcinoma cells (MCF-7aro and T47Daro) transfected with aromatase full gene were used to explore the mechanisms of the two compounds. They dose and time-dependently suppressed aromatase activity in MCF-7aro and T47Daro cells in the nanomole range. However, they neither directly inhibited aromatase, nor improved aromatase degradation even at much higher concentrations. They could also suppress androgen stimulated cell growth, but did not affect estrogen enhanced cell proliferation. These results suggest that compound A and B selectively interfere with aromatase in breast cancer cells, but not estrogen receptor(ER) downstream to disrupt androgen mediated cell growth. Interestingly, compound B effectively inhibited LTED (long term estrogen deprived MCF-7aro cell) cell growth, which is a model for AIs resistance, with an IC50 of 4.68 ± 0.54µM. The results indicate that compound B could potentially overcome AI resistance in breast cancer cell and could be used as a lead to design more potent derivatives.

Su, Bin; Cai, Xiaohan; Hong, Yanyan; Chen, Shiuan

2010-01-01

56

Anti-inflammatory therapy with a COX-2 inhibitor in Tourette's syndrome.  

PubMed

An infectious/inflammatory process plays a role in at least a subgroup of patients with tics and Tourette's syndrome (TS). Successful antibiotic therapy and prophylaxis was described repeatedly. We report the case of a patient suffering from chronic TS who was treated with celecoxib additionally to the antibiotic prophylaxis. This treatment was associated with a continuous improvement of tics and disturbed behaviour, such as aggression and social withdrawal. The withdrawal of celecoxib led to a marked deterioration in TS symptoms while the re-exposition had advantageous therapeutic effects. This result of the treatment with a COX-2 inhibitor supports the view that COX-2 inhibitors show therapeutic benefit in patients suffering from psychiatric disorders in which an inflammatory process is involved in the pathophysiology. PMID:15527551

Müller, Norbert

2004-01-01

57

Substrate-selective COX-2 inhibition decreases anxiety via endocannabinoid activation  

PubMed Central

Augmentation of endogenous cannabinoid (eCB) signaling represents an emerging approach to the treatment of affective disorders. Cyclooxygenase-2 (COX-2) oxygenates arachidonic acid to form prostaglandins, but also inactivates eCBs in vitro. However, the viability of COX-2 as a therapeutic target for in vivo eCB augmentation has not been explored. Here we utilized medicinal chemistry and in vivo analytical and behavioral pharmacological approaches to demonstrate a key role for COX-2 in the regulation of endocannabinoid (eCB) levels in vivo. A novel pharmacological strategy involving “substrate-selective” inhibition of COX-2 was used to augment eCB signaling without affecting related non-eCB lipids or prostaglandin synthesis. Behaviorally, substrate-selective inhibition of COX-2reducedanxiety-like behaviors in mice via increasede CB signaling. These data elucidate a key role for COX-2 in the regulation of eCB signaling and suggest substrate-selective pharmacology represents a viable approach for eCB augmentation with broad therapeutic potential.

Hermanson, Daniel J.; Hartley, Nolan D.; Gamble-George, Joyonna; Brown, Naoko; Shonesy, Brian C.; Kingsley, Phillip J.; Colbran, Roger J.; Reese, Jeffrey

2013-01-01

58

A COX-2 inhibitor enhances the antitumor effects of chemotherapy and radiotherapy for esophageal squamous cell carcinoma.  

PubMed

Cyclooxygenase-2 (COX-2) is a key enzyme of prostaglandin (PG) synthesis that has been demonstrated to be overexpressed in several types of cancers. The function of COX-2 in tumor progression has been recently elucidated. In tumors in which COX-2 is overexpressed, the antitumor effects are suppressed. We examined the effects of celecoxib, a COX-2 inhibitor, in enhancing the antitumor effects of chemotherapy and radiotherapy for esophageal squamous cell carcinoma (ESCC) by reducing the COX-2 activity. We used the human esophageal squamous cell lines TE2 and T.Tn treated with celecoxib and 5-FU/radiation, after which cell viability assays were performed. Changes in the expressions of dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT) mRNA and PGE2 were also measured. In addition, apoptotic changes, and the invasion and migration activity in both the celecoxib and 5-FU treated cells were evaluated. The experiments showed that T.Tn and TE2 proliferation was strongly inhibited by the combination of 5-FU/radiation and the COX-2 inhibitor. Inhibiting the COX-2 activity induced a reduction in PGE2 levels in TE2/T.Tn cells. Following treatment with the COX-2 inhibitor and 5-FU, the OPRT expression was upregulated and the DPD expression was downregulated in the resistant cells. In addition, the combination treatment with the COX-2 inhibitor and 5-FU markedly inhibited both the cell invasion and migration activity. Therefore, COX-2 inhibitors can be useful enhancers of antitumor drugs and radiotherapy for ESCC. PMID:24535229

Yusup, Gulbostan; Akutsu, Yasunori; Mutallip, Muradil; Qin, Wei; Hu, Xin; Komatsu-Akimoto, Aki; Hoshino, Isamu; Hanari, Naoyuki; Mori, Mikito; Akanuma, Naoki; Isozaki, Yuka; Matsubara, Hisahiro

2014-04-01

59

QSAR investigations on benzylideneamino and phenyliminomethyl scaffolds for selective COX-2 inhibiton: a Hansch approach.  

PubMed

Cyclooxygenase inhibitory and selectivity profile of a combined series of thirty one aryl sulphonamide compounds possessing 4-benzylideneamino or 4-phenyliminomethyl scaffolds were subjected to QSAR study using Hansch approach. The compounds in the selected series were characterized using classical aromatic substituent constants like hydrophobicity (pi), molar refractivity (MR), Hammett electronic (sigma), electronic field effect (F), resonance effect (R), and some indicator variables encoding molecular group contributions. Statistically significant QSAR models were generated using multiple regression analysis and cross-validation tools. The derived QSAR models demonstrated that the COX-2 selectivity over COX-1 is predominantly influenced by the central core -N=C- of the diaryl system. Further, the study also indicated that the electronic properties and structural variation in the para position of the phenyl ring (B) governs the COX-2 selectivity of the title compounds. The derived results reveal the important structural features significant for improved COX-2 inhibitory activity and selectivity of these novel aryl sulfonamides. PMID:19534677

Manivannan, E; Chaturvedi, S C

2009-09-01

60

Prescribing of COX-2 inhibitors in Germany after safety warnings and market withdrawals.  

PubMed

The emergence of safety concerns associated with the use of selective cyclooxygenase-2 (COX-2) inhibitors (coxibs) led to market withdrawals of rofecoxib in September 2004 and valdecoxib in April 2005. These events were accompanied by safety alerts from drug authorities and recommendations from professional medical associations. This study analysed the temporal influence of these measures on drug use in Germany, with the objective to assess overall appropriateness of prescribing and to evaluate the potential for pharmaceutical interventions. Drug prescriptions for patients within the statutory health insurance system (GKV) were analysed based on the total amount of DDDs of single drug substances dispensed every month in German pharmacies. The market withdrawal of rofecoxib in September 2004 resulted initially in increased prescribing of other coxibs. New safety warnings on coxibs later in 2004 and the withdrawal of valdecoxib in April 2005 led to pronounced reductions in coxib prescribing. Comparing the third quarter of 2005 with 2004, coxib prescriptions dropped from 47.5 to 10.4 million DDDs. Conversely, in the same time frame, NSAID prescriptions increased by 19.0 million DDDs. This is mostly due to increased prescribing of ibuprofen, diclofenac and, to a lesser degree, meloxicam, acemetacin, piroxicam, and naproxen. However, total prescribing of inhibitors of cyclooxygenases decreased by about 8.4%, indicating a relative reluctance to prescribe these drugs after cardiovascular safety warnings have been issued by drug authorities. Unexpectedly, also prescribing of metamizol (dipyrone) increased by 2.8 million DDDs (20%), despite recommendations to limit its use by medical associations. Furthermore, increased prescribing of proton pump inhibitors of 12.6 million DDDs could be observed. NSAIDs and coxibs are to a larger extent prescribed by a broad range of medical specialist groups including orthopaedists and surgeons, whereas drugs used in gastrointestinal or cardiovascular disorders are mainly prescribed by general practitioners and internal specialists, respectively. Therefore, the individual physician may not always be aware of the risk profiles of their patients. Pharmacists can close this gap by providing comprehensive medication records and information on self medication used by the patient to prescribing practitioners, thereby contributing to improved patient safety. PMID:17069430

Schüssel, K; Schulz, M

2006-10-01

61

Suppression of colitis-related mouse colon carcinogenesis by a COX-2 inhibitor and PPAR ligands  

PubMed Central

Background It is generally assumed that inflammatory bowel disease (IBD)-related carcinogenesis occurs as a result of chronic inflammation. We previously developed a novel colitis-related mouse colon carcinogenesis model initiated with azoxymethane (AOM) and followed by dextran sodium sulfate (DSS). In the present study we investigated whether a cyclooxygenase (COX)-2 inhibitor nimesulide and ligands for peroxisome proliferator-activated receptors (PPARs), troglitazone (a PPAR? ligand) and bezafibrate (a PPAR? ligand) inhibit colitis-related colon carcinogenesis using our model to evaluate the efficacy of these drugs in prevention of IBD-related colon carcinogenesis. Methods Female CD-1 (ICR) mice were given a single intraperitoneal administration of AOM (10 mg/kg body weight) and followed by one-week oral exposure of 2% (w/v) DSS in drinking water, and then maintained on the basal diets mixed with or without nimesulide (0.04%, w/w), troglitazone (0.05%, w/w), and bezafibrate (0.05%, w/w) for 14 weeks. The inhibitory effects of dietary administration of these compounds were determined by histopathological and immunohistochemical analyses. Results Feeding with nimesulide and troglitazone significantly inhibited both the incidence and multiplicity of colonic adenocarcinoma induced by AOM/DSS in mice. Bezafibrate feeding significantly reduced the incidence of colonic adenocarcinoma, but did not significantly lower the multiplicity. Feeding with nimesulide and troglitazone decreased the proliferating cell nuclear antigen (PCNA)-labeling index and expression of ?-catenin, COX-2, inducible nitric oxide synthase (iNOS) and nitrotyrosine. The treatments increased the apoptosis index in the colonic adenocarcinoma. Feeding with bezafibrate also affected these parameters except for ?-catenin expression in the colonic malignancy. Conclusion Dietary administration of nimesulide, troglitazone and bezafibrate effectively suppressed the development of colonic epithelial malignancy induced by AOM/DSS in female ICR mice. The results suggest that COX-2 inhibitor and PPAR ligands could serve as an effective agent against colitis-related colon cancer development.

Kohno, Hiroyuki; Suzuki, Rikako; Sugie, Shigeyuki; Tanaka, Takuji

2005-01-01

62

Apricoxib, a Novel Inhibitor of COX-2, Markedly Improves Standard Therapy Response in Molecularly Defined Models of Pancreatic Cancer  

PubMed Central

Purpose COX-2 is expressed highly in pancreatic cancer and implicated in tumor progression. COX-2 inhibition can reduce tumor growth and augment therapy. The precise function of COX-2 in tumors remains poorly understood, but it is implicated in tumor angiogenesis, evasion of apoptosis, and induction of epithelial-to-mesenchymal transition (EMT). Current therapeutic regimens for pancreatic cancer are minimally effective, highlighting the need for novel treatment strategies. Here, we report that apricoxib, a novel COX-2 inhibitor in phase II clinical trials, significantly enhances the efficacy of gemcitabine/ erlotinib in preclinical models of pancreatic cancer. Experimental Design Human pancreatic cell lines were evaluated in vitro and in vivo for response to apricoxib ± standard-of-care therapy (gemcitabine + erlotinib). Tumor tissue underwent posttreatment analysis for cell proliferation, viability, and EMT phenotype. Vascular parameters were also determined. Results COX-2 inhibition reduced the IC50 of gemcitabine ± erlotinib in six pancreatic cancer cell lines tested in vitro. Furthermore, apricoxib increased the antitumor efficacy of standard combination therapy in several orthotopic xenograft models. In vivo apricoxib combination therapy was only effective at reducing tumor growth and metastasis in tumors with elevated COX-2 activity. In each model examined, treatment with apricoxib resulted in vascular normalization without a decrease in microvessel density and promotion of an epithelial phenotype by tumor cells regardless of basal COX-2 expression. Conclusions Apricoxib robustly reverses EMT and augments standard therapy without reducing microvessel density and warrants further clinical evaluation in patients with pancreatic cancer.

Kirane, Amanda; Toombs, Jason E.; Ostapoff, Katherine; Carbon, Juliet G.; Zaknoen, Sara; Braunfeld, Jordan; Schwarz, Roderich E.; Burrows, Francis J.; Brekken, Rolf A.

2013-01-01

63

Complexation of cox-2 inhibitors with bovine serum albumin: interaction mechanism.  

PubMed

Mechanism of interaction of six cox-2 inhibitors--celecoxib, valdecoxib, etoricoxib, parecoxib sodium, meloxicam and nimesulide--with bovine serum albumin (BSA) was studied using fluorescence spectroscopic technique. Results were discussed in terms of the binding parameters, thermodynamics of the binding process, the nature of forces involved in the interaction and the fluorescence quenching mechanism involved. Association constants were of the order of 10(4)-10(5) for various drugs. Binding affinity varied with the nature of drug. Nature of forces involved in the interaction could be predicted from the thermodynamic parameters for the binding. Meloxicam and nimesulide shared common sites with hydrophobic probe, 1-anilinonaphthalene-8-sulfonate (ANS) on BSA molecule. Stern-Volmer analysis of the quenching data indicated that both tryptophan residues of BSA are fully accessible to the drugs and predominantly static quenching mechanism is involved in the interaction. PMID:19235548

Seedher, Neelam; Bhatia, Sonu

2009-01-01

64

Enhancing the pharmacodynamic profile of a class of selective COX-2 inhibiting nitric oxide donors.  

PubMed

We report herein the development, synthesis, physicochemical and pharmacological characterization of a novel class of pharmacodynamic hybrids that selectively inhibit cyclooxygenase-2 (COX-2) isoform and present suitable nitric oxide releasing properties. The replacement of the ester moiety with the amide group gave access to in vivo more stable and active derivatives that highlighted outstanding pharmacological properties. In particular, the glycine derivative proved to be extremely active in suppressing hyperalgesia and edema. PMID:24373735

Biava, Mariangela; Battilocchio, Claudio; Poce, Giovanna; Alfonso, Salvatore; Consalvi, Sara; Di Capua, Angela; Calderone, Vincenzo; Martelli, Alma; Testai, Lara; Sautebin, Lidia; Rossi, Antonietta; Ghelardini, Carla; Di Cesare Mannelli, Lorenzo; Giordani, Antonio; Persiani, Stefano; Colovic, Milena; Dovizio, Melania; Patrignani, Paola; Anzini, Maurizio

2014-01-15

65

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

PubMed Central

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.

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

2012-01-01

66

Improvement in gastrointestinal tolerability of the selective cyclooxygenase (COX)-2 inhibitor, meloxicam, compared with piroxicam: results of the Safety and Efficacy Large-scale Evaluation of COX inhibiting Therapies (SELECT) trial in osteoarthritis  

Microsoft Academic Search

SUMMARY Select is a large-scale, prospective, international, multicentre, double-blind, double-dummy, randomized, parallel-group trial. Patients with exacerbation of osteoarthritis were treated with the recommended dose of meloxicam (7.5 mg) or piroxicam (20 mg) once daily for 28 days; 4320 patients were administered meloxicam and 4336 piroxicam. The incidence of adverse events was significantly lower in the meloxicam group (22.5%) compared with

J. DEQUEKER; C. HAWKEY; A. KAHAN; K. STEINBRUCK; C. ALEGRE; E. BAUMELOU; B. BEGAUD; H. ISOMAKI; G. LITTLEJOHN; J. MAU; S. PAPAZOGLOU

1998-01-01

67

Anti-hyperalgesic activity of the cox-2 inhibitor lumiracoxib in a model of bone cancer pain in the rat  

Microsoft Academic Search

Chronic pain resulting from metastatic bone cancer remains poorly understood and resistant to treatment. Here we have examined the effect of the novel COX-2 enzyme inhibitor lumiracoxib in a model of bone cancer pain in the rat. Lumiracoxib was administered orally twice daily from day 10 to day 20 after injection of MRMT-1 tumour cells into one tibia. Mechanical hyperalgesia,

Alyson Fox; Stephen Medhurst; Jean-Philippe Courade; Marcus Glatt; Janet Dawson; Laszlo Urban; Stuart Bevan; Isabel Gonzalez

2004-01-01

68

Effect of the COX2 Inhibitor Celecoxib on Behavioural and Immune Changes in an Olfactory Bulbectomised Rat Model of Depression  

Microsoft Academic Search

Background: The olfactory bulbectomised (OBX) rat model is a chronic model of depression in which behavioural and neuroimmunoendocrine changes are reversed only after chronic antidepressant treatment. The cyclooxygenase 2 (COX-2) inhibitor celecoxib has been shown to improve the depressive symptoms in patients with major depression. Methods: The association between blood and brain immunological and behavioural changes in chronic treatment with

Aye Mu Myint; Harry W. M. Steinbusch; Liam Goeghegan; Dirk Luchtman; Yong Ku Kim; Brian E. Leonard

2007-01-01

69

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

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

70

Phase II nonrandomized study of the efficacy and safety of COX2 inhibitor celecoxib on patients with cancer cachexia  

Microsoft Academic Search

Chronic inflammation is one of the main features of cancer cachexia. Experimental and clinical studies showed that cyclooxygenase-2\\u000a inhibitors, such as celecoxib, may be beneficial in counteracting major symptoms of this devastating syndrome. We carried\\u000a out a prospective phase II clinical trial to test the safety and effectiveness of an intervention with the COX-2 inhibitor\\u000a celecoxib (300 mg\\/day for 4 months) on

Giovanni Mantovani; Antonio Macciò; Clelia Madeddu; Roberto Serpe; Giorgia Antoni; Elena Massa; Mariele Dessì; Filomena Panzone

2010-01-01

71

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

National Technical Information Service (NTIS)

Aromatase (CYP19) is responsible for estrogen biosynthesis, and CYP- 19 and cyclooxygenase-2 (COX-2) are both overexpressed in human breast cancers. Prostaglandin activates the CYP19 promotor and increases gene expression therefore we hypothesized that ce...

C. L. Shapiro

2006-01-01

72

The COX-2 Selective Blocker Etodolac Inhibits TNF?-Induced Apoptosis in Isolated Rabbit Articular Chondrocytes  

PubMed Central

Chondrocyte apoptosis contributes to the disruption of cartilage integrity in osteoarthritis (OA). Recently, we reported that activation of volume-sensitive Cl? current (ICl,vol) mediates cell shrinkage, triggering apoptosis in rabbit articular chondrocytes. A cyclooxygenase (COX) blocker is frequently used for the treatment of OA. In the present study, we examined in vitro effects of selective blockers of COX on the TNF?-induced activation of ICl,vol in rabbit chondrocytes using the patch-clamp technique. Exposure of isolated chondrocytes to TNF? resulted in an obvious increase in membrane Cl? conductance. The TNF?-evoked Cl? current exhibited electrophysiological and pharmacological properties similar to those of ICl,vol. Pretreatment of cells with selective COX-2 blocker etodolac markedly inhibited ICl,vol activation by TNF? as well as subsequent apoptotic events such as apoptotic cell volume decrease (AVD) and elevation of caspase-3/7 activity. In contrast, a COX-1 blocker had no effect on the decrease in cell volume or the increase in caspase-3/7 activity induced by TNF?. Thus, the COX-2-selective blocker had an inhibitory effect on TNF?-induced apoptotic events, which suggests that this drug would have efficacy for the treatment of OA.

Kumagai, Kousuke; Kubo, Mitsuhiko; Imai, Shinji; Toyoda, Futoshi; Maeda, Tsutomu; Okumura, Noriaki; Matsuura, Hiroshi; Matsusue, Yoshitaka

2013-01-01

73

HMG-CoA reductase inhibitors induce COX-2 gene expression in murine macrophages: role of MAPK cascades and promoter elements for CREB and C/EBPbeta.  

PubMed

Except functioning as lipid-lowering agents, HMG-CoA inhibitors, statins, are good tools to clarify the signaling role of small G proteins. In this study, we found in murine RAW264.7 macrophages, statins within 1-30 microM stimulated COX-2 gene transcription and PGE(2) formation, displaying potencies as lovastatin > fluvastatin > atorvastatin > pravastatin. Transfection experiments with COX-2 promoter construct showed the necessity of C/EBPbeta and CRE promoter sites, but not NF-kappaB promoter site. Effects of statins on the activation of COX-2 promoter, induction of COX-2 protein, and PGE(2) production were all prevented by mevalonate and prenylated metabolites, FPP and GGPP. Consistent with the effect of statins, manumycin A, farnesyltransferase inhibitor, and geranylgeranyltransferase inhibitor increased PGE(2) production and COX-2 induction. Likewise, toxin B, an inhibitor of Rho family members, caused a prominent COX-2 induction. Results also indicated that tyrosine kinase, ERK, and p38 MAPK play essential roles in statin action. Taken together, these results not only demonstrate a unique action of statins in the upregulation of COX-2 expression in macrophages, but also suggest a negative role controlled by small G proteins in COX-2 gene regulation. Removal of this negative control by impairing G protein prenylation with statins leads to MAPKs activation and promotes COX-2 gene expression through the activation at CRE and C/EBPbeta sites. PMID:15530865

Chen, Jui-Ching; Huang, Kuo-Chin; Wingerd, Byron; Wu, Wen-Tung; Lin, Wan-Wan

2004-12-10

74

COX-2 expression is predictive for early relapse and aromatase inhibitor resistance in patients with ductal carcinoma in situ of the breast, and is a target for treatment.  

PubMed

Background:Stratification of patients for treatment of ductal carcinoma in situ (DCIS) is suboptimal, with high systemic overtreatment rates.Methods:A training set of 95 tumours from women with pure DCIS were immunostained for proteins involved in cell survival, hypoxia, growth factor and hormone signalling. A generalised linear regression with regularisation and variable selection was applied to a multiple covariate Cox survival analysis with recurrence-free survival 10-fold cross-validation and leave-one-out iterative approach were used to build and test the model that was validated using an independent cohort of 58 patients with pure DCIS. The clinical role of a COX-2-targeting agent was then tested in a proof-of-concept neoadjuvant randomised trial in ER-positive DCIS treated with exemestane 25?mg?day(-1)±celecoxib 800?mg?day(-1).Results:The COX-2 expression was an independent prognostic factor for early relapse in the training (HR 37.47 (95% CI: 5.56-252.74) P=0.0001) and independent validation cohort (HR 3.9 (95% CI: 1.8-8.3) P=0.002). There was no significant interaction with other clinicopathological variables. A statistically significant reduction of Ki-67 expression after treatment with exemestane±celecoxib was observed (P<0.02) with greater reduction in the combination arm (P<0.004). Concomitant reduction in COX-2 expression was statistically significant in the exemestane and celecoxib arm (P<0.03) only.Conclusions:In patients with DCIS, COX-2 may predict recurrence, aiding clinical decision making. A combination of an aromatase inhibitor and celecoxib has significant biological effect and may be integrated into treatment of COX2-positive DCIS at high risk of recurrence. PMID:24874483

Generali, D; Buffa, F M; Deb, S; Cummings, M; Reid, L E; Taylor, M; Andreis, D; Allevi, G; Ferrero, G; Byrne, D; Martinotti, M; Bottini, A; Harris, A L; Lakhani, S R; Fox, S B

2014-07-01

75

Perioperative Use of ?-blockers and COX-2 Inhibitors May Improve Immune Competence and Reduce the Risk of Tumor Metastasis  

PubMed Central

Background COX inhibitors and ?-blockers were recently suggested to reduce cancer progression through inhibition of tumor proliferation and growth factor secretion, induction of tumor apoptosis, and prevention of cellular immune suppression during the critical perioperative period. Here we evaluated the perioperative impact of clinically applicable drugs from these categories in the context of surgery, studying natural killer (NK) cell activity and resistance to experimental metastases. Methods F344 rats were treated with COX-1 inhibitors (SC560), COX-2 inhibitors (indo-methacin, etodolac, or celecoxib), a ?-blocker (propranolol), or a combination of a COX-2 inhibitor and a ?-blocker (etodolac and propranolol). Rats underwent laparotomy, and were inoculated intravenously with syngeneic MADB106 tumor cells for the assessment of lung tumor retention (LTR). Additionally, the impact of these drug regimens on postoperative levels of NK cytotoxicity was studied in peripheral blood and marginating-pulmonary leukocytes. Results Surgery increased MADB106 LTR. COX-2 inhibition, but not COX-1 inhibition, reduced postoperative LTR. Etodolac and propranolol both attenuated the deleterious impact of surgery, and their combined use abolished it. Surgery decreased NK cytotoxicity per NK cell in both immune compartments, and only the combination of etodolac and propranolol significantly attenuated these effects. Lastly, the initiation of drug treatment three days prior to surgery yielded the same beneficial effects as a single pre-operative administration, but, as discussed, prolonged treatment may be more advantageous clinically. Conclusions Excess prostaglandin and catecholamine release contributes to postoperative immune-suppression. Treatment combining perioperative COX-2 inhibition and ?-blockade is practical in operated cancer patients, and our study suggests potential immunological and clinical benefits.

Benish, Marganit; Bartal, Inbal; Goldfarb, Yael; Levi, Ben; Avraham, Roi; Raz, Amiram; Ben-Eliyahu, Shamgar

2013-01-01

76

Effects of COX-2 inhibitor NS-398 on IL-10 expression in rat fungal keratitis  

PubMed Central

AIM To investigate the expression of interleukin-10 (IL-10) and the effect of NS-398(COX-2 inhibitor) on the expression of IL-10 in fungal keratitis in rats, and analyze its effects on anti-fungus immunity. METHODS Ninety Wister rats were randomly divided into 3 groups. Group A was blank control group (10 eyes). Group B was fungal keratitis group (40 eyes). Group C was fungal keratitis group treated with NS-398 (40 eyes). PAS staining, 100g/L potassium hydroxide (KOH) smear and fungal culture confirmed the successful establishment of fungal keratitis model. After the central epithelium was scraped, Fusarium solani colonies were applied and contact lens was put on the right cornea of group B and C, and plane contact lens was put on the left cornea of control eyes. Phosphate buffered saline (PBS) eyedrops were given for group B and NS-398 eyedrops for group C. The expression of IL-10 on corneas of group B and C on the 1st day, 3rd days, 7th days, and 14th days were detected by immunohistochemistry and semi- quantitative reverse transcription- polymerase chain reaction (RT-PCR). RESULTS Histopathologic examination showed neutrophil infiltration and severe tissue necrosis in ulcer cornea. PAS staining confirmed the existence of hyphae and spores in the superficial layer of stroma. In the blank and control groups almost no expression of IL-10 was detected at any observing points. In group B the expression of IL-10 increased at first and decreased thereafter. Its expression also showed significant difference at any observing points (P<0.01). Compared with group B, the expression of IL-10 in group C showed no difference on the 1st day, decrease on the 3rd day, but a significant increase on the 7th day and 14th day. CONCLUSION IL-10 takes part in the occurrence and development of fungal keratitis. NS-398 can upgrade the expression of IL-10 in fungal keratitis in the later period of the ulcer. Meanwhile, pathologic observation showed a slightly corneal opacity. IL-10 may play an important role in the process of cornea anti-damage repair.

Li, Na; Che, Cheng-Ye; Hu, Li-Ting; Lin, Jing; Wang, Qing; Zhao, Gui-Qiu

2011-01-01

77

Re: use of cyclo-oxygenase 2 inhibitors (COX2) and prescription non-steroidal anti-inflammatory drugs(NSAIDS) in UK and USA populations: implications for COX2 cardiovascular profile  

Microsoft Academic Search

We read the paper by Arellano et al. describing the\\u000achannelling of cyclo-oxygenase 2 inhibitors (COX-2)\\u000aand non-steroidal anti-inflammatory drugs (NSAIDs)\\u000ain UK and USA populations1 using databases they\\u000adescribe as generally thought to be representative ...

Tjeerd P. van Staa; J. Parkinson

2007-01-01

78

5Heteroatom substituted pyrazoles as canine COX2 inhibitors. Part 1: Structure–activity relationship studies of 5-alkylamino pyrazoles and discovery of a potent, selective, and orally active analog  

Microsoft Academic Search

Structure–activity relationship (SAR) studies of the novel 2-[3-di and trifluoromethyl-5-alkylamino pyrazo-1-yl]-5-methanesulfonyl (SO2Me)\\/sulfamoyl (SO2NH2)-pyridine derivatives for canine COX enzymes are described. The studies led to the identification of 2e as lead with potent in vitro activity, selectivity, and in vivo activity in dogs and cats.

Subas M. Sakya; Kristin M. Lundy DeMello; Martha L. Minich; Bryson Rast; Andrei Shavnya; Robert J. Rafka; David A. Koss; Hengmiao Cheng; Jin Li; Burton H. Jaynes; Carl B. Ziegler; Donald W. Mann; Carol F. Petras; Scott B. Seibel; Annette M. Silvia; David M. George; Lisa A. Lund; Suzanne St. Denis; Anne Hickman; Michelle L. Haven; Michael P. Lynch

2006-01-01

79

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

PubMed Central

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.

Dadiboyena, Sureshbabu; Nefzi, Adel

2011-01-01

80

Hepatic Ischemia and Reperfusion Injury in the Absence of Myeloid Cell-Derived COX-2 in Mice  

PubMed Central

Cyclooxygenase-2 (COX-2) is a mediator of hepatic ischemia and reperfusion injury (IRI). While both global COX-2 deletion and pharmacologic COX-2 inhibition ameliorate liver IRI, the clinical use of COX-2 inhibitors has been linked to increased risks of heart attack and stroke. Therefore, a better understanding of the role of COX-2 in different cell types may lead to improved therapeutic strategies for hepatic IRI. Macrophages of myeloid origin are currently considered to be important sources of the COX-2 in damaged livers. Here, we used a Cox-2flox conditional knockout mouse (COX-2?M/?M) to examine the function of COX-2 expression in myeloid cells during liver IRI. COX-2?M/?M mice and their WT control littermates were subjected to partial liver ischemia followed by reperfusion. COX-2?M/?M macrophages did not express COX-2 upon lipopolysaccharide stimulation and COX-2?M/?M livers showed reduced levels of COX-2 protein post-IRI. Nevertheless, selective deletion of myeloid cell-derived COX-2 failed to ameliorate liver IRI; serum transaminases and histology were comparable in both COX-2?M/?M and WT mice. COX-2?M/?M livers, like WT livers, developed extensive necrosis, vascular congestion, leukocyte infiltration and matrix metalloproteinase-9 (MMP-9) expression post-reperfusion. In addition, myeloid COX-2 deletion led to a transient increase in IL-6 levels after hepatic reperfusion, when compared to controls. Administration of celecoxib, a selective COX-2 inhibitor, resulted in significantly improved liver function and histology in both COX-2?M/?M and WT mice post-reperfusion, providing evidence that COX-2-mediated liver IRI is caused by COX-2 derived from a source(s) other than myeloid cells. In conclusion, these results support the view that myeloid COX-2, including myeloid-macrophage COX-2, is not responsible for the hepatic IRI phenotype.

Duarte, Sergio; Kato, Hiroyuki; Kuriyama, Naohisa; Suko, Kathryn; Ishikawa, Tomo-o; Busuttil, Ronald W.; Herschman, Harvey R.; Coito, Ana J.

2014-01-01

81

Hepatic ischemia and reperfusion injury in the absence of myeloid cell-derived COX-2 in mice.  

PubMed

Cyclooxygenase-2 (COX-2) is a mediator of hepatic ischemia and reperfusion injury (IRI). While both global COX-2 deletion and pharmacologic COX-2 inhibition ameliorate liver IRI, the clinical use of COX-2 inhibitors has been linked to increased risks of heart attack and stroke. Therefore, a better understanding of the role of COX-2 in different cell types may lead to improved therapeutic strategies for hepatic IRI. Macrophages of myeloid origin are currently considered to be important sources of the COX-2 in damaged livers. Here, we used a Cox-2flox conditional knockout mouse (COX-2-M/-M) to examine the function of COX-2 expression in myeloid cells during liver IRI. COX-2-M/-M mice and their WT control littermates were subjected to partial liver ischemia followed by reperfusion. COX-2-M/-M macrophages did not express COX-2 upon lipopolysaccharide stimulation and COX-2-M/-M livers showed reduced levels of COX-2 protein post-IRI. Nevertheless, selective deletion of myeloid cell-derived COX-2 failed to ameliorate liver IRI; serum transaminases and histology were comparable in both COX-2-M/-M and WT mice. COX-2-M/-M livers, like WT livers, developed extensive necrosis, vascular congestion, leukocyte infiltration and matrix metalloproteinase-9 (MMP-9) expression post-reperfusion. In addition, myeloid COX-2 deletion led to a transient increase in IL-6 levels after hepatic reperfusion, when compared to controls. Administration of celecoxib, a selective COX-2 inhibitor, resulted in significantly improved liver function and histology in both COX-2-M/-M and WT mice post-reperfusion, providing evidence that COX-2-mediated liver IRI is caused by COX-2 derived from a source(s) other than myeloid cells. In conclusion, these results support the view that myeloid COX-2, including myeloid-macrophage COX-2, is not responsible for the hepatic IRI phenotype. PMID:24819536

Duarte, Sergio; Kato, Hiroyuki; Kuriyama, Naohisa; Suko, Kathryn; Ishikawa, Tomo-O; Busuttil, Ronald W; Herschman, Harvey R; Coito, Ana J

2014-01-01

82

Maturation and Fertilization of Non-Human Primate Oocytes are Compromised by Oral Administration of a COX2 Inhibitor  

PubMed Central

Objective To determine if oral administration of a cyclooxygenase-2 (COX2) inhibitor affects oocyte nuclear maturation and fertilization in non-human primates. Design Laboratory research study. Setting Medical school. Animals Adult female cynomolgus monkeys (Macaca fascicularis). Interventions Monkeys received gonadotropins to stimulate multiple follicular development. An ovulatory dose of human chorionic gonadotropin (hCG) was administered either alone or concomitant with oral celecoxib, a COX2 inhibitor; oocytes were retrieved 36 hours later and exposed to sperm in vitro. Main Outcome Measures Oocytes were assessed for nuclear status at retrieval, resumption of meiosis in vitro, and success of in vitro fertilization. Results Treatment with hCG alone yielded oocytes which were primarily at the meiosis II (MII) stage of nuclear maturation (72.9%); few oocytes were obtained at the germinal vesicle (GV) and germinal vesicle break down (GVBD) stages. Treatment with hCG and celecoxib yielded fewer mature (MII) oocytes (35.6%) and more oocytes at less mature stages when compared to oocytes from monkeys treated with hCG alone. The majority (68.3±15.9%) of MII oocytes from monkeys treated with hCG alone fertilized in vitro, compared with only 11.0±5.9% of MII oocytes from monkeys treated with hCG and celecoxib. Conclusions Oral administration of a COX2 inhibitor reduced the rate of oocyte nuclear maturation and the success of in vitro fertilization. Drugs of this class may block multiple essential steps in female reproduction and be effective contraceptives for women.

Duffy, Diane M.; VandeVoort, Catherine A.

2011-01-01

83

Pharmacophore generation and atom-based 3D-QSAR of novel 2-(4-methylsulfonylphenyl)pyrimidines as COX-2 inhibitors.  

PubMed

Cyclooxygenase-2 (COX-2) inhibitors are widely used for the treatment of pain and inflammatory disorders such as rheumatoid arthritis and osteoarthritis. A series of novel 2-(4-methylsulfonylphenyl)pyrimidine derivatives has been reported as COX-2 inhibitors. In order to understand the structural requirement of these COX-2 inhibitors, a ligand-based pharmacophore and atom-based 3D-QSAR model have been developed. A five-point pharmacophore with four hydrogen bond acceptors (A) and one hydrogen bond donor (D) was obtained. The pharmacophore hypothesis yielded a 3D-QSAR model with good partial least-square (PLS) statistics results. The training set correlation is characterized by PLS factors (r (2) = 0.642, SD = 0.65, F = 82.7, P = 7.617 e - 12). The test set correlation is characterized by PLS factors (Q (2) (ext) = 0.841, RMSE = 0.24,Pearson-R = 0.91). A docking study revealed the binding orientations of these inhibitors at active site amino acid residues (Arg513, Val523, Phe518, Ser530, Tyr355, His90) of COX-2 enzyme. The results of ligand-based pharmacophore hypothesis and atom-based 3D-QSAR give detailed structural insights as well as highlights important binding features of novel 2-(4-methylsulfonylphenyl)pyrimidine derivatives as COX-2 inhibitors which can provide guidance for the rational design of novel potent COX-2 inhibitors. PMID:19669924

Shah, Ujashkumar A; Deokar, Hemantkumar S; Kadam, Shivajirao S; Kulkarni, Vithal M

2010-08-01

84

Effect of 5-LOX/COX-2 common inhibitor DHDMBF30 on pancreatic cancer cell Capan2  

PubMed Central

AIM: To study the effect of 5-lipoxygenase/cyclooxy-genase-2 (5-LOX/COX-2) dual inhibitor 7-tert-butyl-2, 3-dihydro-3, 3-dimethyl substituted dihydrofuran 30 (DHDMBF30) on proliferation and apoptosis of the pancreatic cancer cell line Capan-2 and the effect of DHDMBF30 on human pancreatic cancer in a nude mouse model. METHODS: Investigate the effect of 5-LOX/COX-2 dual inhibitor DHDMBF30 on proliferation and apoptosis of the pancreatic cancer cell line Capan-2 by RT-PCR, MTT assay, FCM and electron microscope. Cell line Capan-2 was inoculated percutaneously on the outer thigh of 12 nude mice. The VEGF mRNA of transplantation tumor was detected by RT-PCR. RESULTS: DHDMBF30 inhibits the proliferation of cell line Capan2, reduces the expression of 5-LOX, COX-2 and VEGF. After Capan2 was treated with DHDMBF30, we found that the apoptosis peak of the experimental group was significantly higher than that of the contrast group (3.08 ± 1.89 vs 27.67 ± 0.52, P < 0.001). The tumor weight of the DHDMBF30 group was significantly lower than PBS control groups (1.35 ± 0.47 vs 2.92 ± 0.73, P < 0.01). Expression of VEGF in the DHDMBF30 group was significantly decreased. CONCLUSION: DHDMBF30 inhibits the proliferation of the pancreatic cell line Capan2, and induces apoptosis and inhibits the growth of pancreatic cancer in nude mice.

Zhang, Bo; Wang, Chang-Liang; Zhao, Wen-Hua; Lv, Ming; Wang, Chun-Ying; Zhong, Wei-Xia; Zhou, Wu-Yuan; Yu, Wen-Sheng; Zhang, Yan; Li, Sheng

2008-01-01

85

A COX-2 inhibitor reduces muscle soreness, but does not influence recovery and adaptation after eccentric exercise.  

PubMed

The aim of this study was to investigate the effect of a cyclooxygenase (COX)-2 inhibitor on the recovery of muscle function, inflammation, regeneration after, and adaptation to, unaccustomed eccentric exercise. Thirty-three young males and females participated in a double-blind, placebo-controlled experiment. Seventy unilateral, voluntary, maximal eccentric actions with the elbow flexors were performed twice (bouts 1 and 2) with the same arm, separated by 3 weeks. The test group participants were administered 400 mg/day of celecoxib for 9 days after bout 1. After both bouts 1 and 2, concentric and isometric force-generating capacity was immediately reduced (approximately 40-50%), followed by the later appearance of muscle soreness and increased serum creatine kinase levels. Radiolabelled autologous leukocytes (detected by scintigraphy) and monocytes/macrophages (histology) accumulated in the exercised muscles, simultaneously with increased satellite cell activity. These responses were reduced and recovery was faster after bout 2 than 1, demonstrating a repeated-bout effect. No differences between the celecoxib and placebo groups were detected, except for muscle soreness, which was attenuated by celecoxib. In summary, celecoxib, a COX-2 inhibitor, did not detectably affect recovery of muscle function or markers of inflammation and regeneration after unaccustomed eccentric exercise, nor did the drug influence the repeated-bout effect. However, it alleviated muscle soreness. PMID:19522751

Paulsen, G; Egner, I M; Drange, M; Langberg, H; Benestad, H B; Fjeld, J G; Hallén, J; Raastad, T

2010-02-01

86

COX-2 and the kidneys.  

PubMed

The kidney is the second most frequent target of serious adverse effects of non-steroidal antiinflammatory drugs (NSAIDs). The renal side effects of NSAIDs related to inhibition of cyclooxygenase (COX) comprise reduction in renal blood flow (RBF) and glomerular filtration rate (GFR), sodium/water retention, water intoxication and hyperkalemia. The discovery of two COX-isoenzymes, a constitutive COX-1, serving homeostatic prostanoid synthesis, and an inducible COX-2, responsible for proinflammatory prosta noid production, led to the development of new NSAIDs: Preferential and specific COX-2 inhibitors, promising minimal NSAID-typical toxicity with equivalent efficacy. However, we learned that there is no clear distinction in "physiologic" constitutive COX-1 and "inflammatory" inducible COX-2. This is particular true for the kidney of humans and other mammalians, where COX-2 was found constitutively in meaningful amounts. Animal experiments and clinical trials with preferential and specific COX-2 inhibitors revealed that COX-2 is the critical enzyme for sodium excretion, renin release and likely antagonism of antidiuretic hormone. Additionally, a significant role of COX-2 for nephro genesis is suggested. For renal hemodynamics the given evidence point to COX-1 as the predominant enzyme, but further investigations are required. In summary, the gain of renal safety by use of preferential or specific COX-2 inhibitors is small or negligible with respect to sodium retention, hyperkalemia and probably water intoxication. These drugs may be advantageous regarding renal perfusion, but presently the same precautions as for conventional NSAIDs must be used. PMID:11102561

Stichtenoth, D O; Frölich, J C

2000-11-01

87

Inhibition of Akt\\/PKB by a COX2 Inhibitor Induces Apoptosis in Gastric Cancer Cells  

Microsoft Academic Search

Background\\/Aim: Inhibition of cyclooxygenase-2 has been proposed to be a potential mechanism for the chemoprevention of gastrointestinal tumors by nonsteroidal anti-inflammatory drugs. This study investigates the mechanisms by which the cyclooxygenase-2 inhibitor SC236 induces apoptosis of gastric cancer cell lines and its downstream signaling pathway. Methods: Two gastric cancer cell lines, AGS and MKN28, were treated with SC236 and assessed

Xiao Ming Fan; Xiao Hua Jiang; Qing Gu; Yick Pang Ching; Hua He; Harry H. X. Xia; Marie Chia Mi Lin; Annie O. O. Chan; Man Fung Yuen; Hsiang-Fu Kung; Benjamin Chun-Yu Wong

2006-01-01

88

Restoration of E-cadherin expression by selective Cox-2 inhibition and the clinical relevance of the epithelial-to-mesenchymal transition in head and neck squamous cell carcinoma  

PubMed Central

Background The epithelial-to-mesenchymal transition (EMT) accompanied by the downregulation of E-cadherin has been thought to promote metastasis. Cyclooxygenase-2 (Cox-2) is presumed to contribute to cancer progression through its multifaceted function, and recently its inverse relationship with E-cadherin was suggested. The aim of the present study was to investigate whether selective Cox-2 inhibitors restore the expression of E-cadherin in head and neck squamous cell carcinoma (HNSCC) cells, and to examine the possible correlations of the expression levels of EMT-related molecules with clinicopathological factors in HNSCC. Methods We used quantitative real-time PCR to examine the effects of three selective Cox-2 inhibitors, i.e., celecoxib, NS-398, and SC-791 on the gene expressions of E-cadherin (CDH-1) and its transcriptional repressors (SIP1, Snail, Twist) in the human HNSCC cell lines HSC-2 and HSC-4. To evaluate the changes in E-cadherin expression on the cell surface, we used a flowcytometer and immunofluorescent staining in addition to Western blotting. We evaluated and statistically analyzed the clinicopathological factors and mRNA expressions of Cox-2, CDH-1 and its repressors in surgical specimens of 40 patients with tongue squamous cell carcinoma (TSCC). Results The selective Cox-2 inhibitors upregulated the E-cadherin expression on the cell surface of the HNSCC cells through the downregulation of its transcriptional repressors. The extent of this effect depended on the baseline expression levels of both E-cadherin and Cox-2 in each cell line. A univariate analysis showed that higher Cox-2 mRNA expression (p?=?0.037), lower CDH-1 mRNA expression (p?=?0.020), and advanced T-classification (p?=?0.036) were significantly correlated with lymph node metastasis in TSCC. A multivariate logistic regression revealed that lower CDH-1 mRNA expression was the independent risk factor affecting lymph node metastasis (p?=?0.041). Conclusions These findings suggest that the appropriately selective administration of certain Cox-2 inhibitors may have an anti-metastatic effect through suppression of the EMT by restoring E-cadherin expression. In addition, the downregulation of CDH-1 resulting from the EMT may be closely involved in lymph node metastasis in TSCC.

2014-01-01

89

COX1, and not COX2 activity, regulates airway function: relevance to aspirin-sensitive asthma  

Microsoft Academic Search

Cyclooxygenase (COX) -1 and COX-2 are expressed in airway cells, where their activities influence functions such as airway hyperreactivity. Clin- ical data show that mixed COX-1\\/COX-2 inhibitors such as aspirin, but not COX-2 selective inhibitors such as rofecoxib, induce bronchoconstriction and asthma in sensitive individuals. This anomaly has not yet been explained. Here, we have used tissue from genetically modified

Louise S. Harrington; Ruth Lucas; Shaun K. McMaster; Laura Moreno; Glenis Scadding; Timothy D. Warner; Jane A. Mitchell

2008-01-01

90

Estrogen stimulation of COX-2-derived PGI2 confers atheroprotection.  

PubMed

Although selective cyclooxygenase-2 (COX-2) inhibitors provide relief from pain and inflammation, they also reduce the formation of the atheroprotective prostaglandin I2 (PGI2). They do not reduce the formation of the COX-1-derived thromboxane A2 (TXA2), however, which is both atherogenic and a potent vasoconstrictor. For this reason, the effects of TXA2 might be exacerbated during extended therapy with COX-2 inhibitors, potentially predisposing patients to heart attack and stroke. Recent studies have demonstrated that the atheroprotective effects of estrogen are induced through PGI2 production, through COX-2 activation. This explains how estrogen production in pre-menopausal females is beneficial for the heart and also raises the possibility that COX-2 inhibitors might be particularly hazardous to females. PMID:15950485

Shah, Bukhtiar H

2005-07-01

91

Design and synthesis of 4-O-methylhonokiol analogs as inhibitors of cyclooxygenase-2 (COX-2) and PGF? production.  

PubMed

A series of novel 4-O-methylhonokiol analogs were synthesized in light of revealing structure-activity relationship for inhibitory effect of COX-2 enzyme. The key strategy of the molecular design was oriented towards modification of the potential metabolic soft spots (e.g., phenol and olefin) or by altering the polar surface area via incorporating heterocycles such as isoxazole and triazole. Most of all exhibited the inhibitory effects on COX-2 and PGF(1) production but not macrophage NO production. Especially, aryl carbamates 10 and 11 exhibited more potent inhibitory activity against COX-2 and PGF(1) production. PMID:22494844

Lee, Bit; Kwak, Jae-Hwan; Huang, Shin-Won; Jang, Jae-Yong; Lim, Sanglae; Kwak, Young-Shin; Lee, Kiho; Kim, Hyung Sook; Han, Sang-Bae; Hong, Jin-Tae; Lee, Heesoon; Song, Sukgil; Seo, Seung-Yong; Jung, Jae-Kyung

2012-05-01

92

Selective increase of neuronal cyclooxygenase-2 (COX2) expression in vulnerable brain regions of rats with experimental Wernicke’s encephalopathy: effect of nimesulide  

Microsoft Academic Search

Thiamine deficiency (TD) in both humans and experimental animals results in severe mitochondrial dysfunction and leads to\\u000a selective neuronal cell death in diencephalic and cerebellar structures. We have investigated cyclooxygenase-2 (COX-2) expression\\u000a in vulnerable (medial thalamus, inferior colliculus) and spared (frontal cortex) regions of rats with thiamine deficiency.\\u000a Expression of COX-2 mRNA was selectively increased (twofold, p?

Baoying Gu; Paul Desjardins; Roger F. Butterworth

2008-01-01

93

Osteoarthritis management: the role of cyclooxygenase-2-selective inhibitors  

Microsoft Academic Search

Background: Cyclooxygenase (COX)-2selective inhibitors are a new type of non-steroidal anti-inflammatory drug (NSAID) for the management of pain caused by osteoarthritis (OA). The most recent OA guidelines from the American College of Rheumatology were published in 2000 because new therapies such as the COX-2selective inhibitors had been introduced for the management of OA.Objective: Because more data are now available on

Thomas J. Schnitzer

2001-01-01

94

5-Heteroatom-substituted pyrazoles as canine COX2 inhibitors: Part 2. Structure–activity relationship studies of 5-alkylethers and 5-thioethers  

Microsoft Academic Search

Structure–activity relationship (SAR) studies of novel 2-[3-trifluoromethyl-5-alkyl(thio)ether pyrazo-1-yl]-5-methanesulfonyl pyridine derivatives for canine COX enzymes are described. The 4-cyano-5-alkyl ethers were found to have excellent potency and selectivity, whereas the 5-thioethers were potent but less selective than the ether analogs in a canine whole blood (CWB) COX-2 assay.

Subas M. Sakya; Hengmiao Cheng; Kristin M. Lundy DeMello; Andrei Shavnya; Martha L. Minich; Bryson Rast; Jason Dutra; Chao Li; Robert J. Rafka; David A. Koss; Jin Li; Burton H. Jaynes; Carl B. Ziegler; Donald W. Mann; Carol F. Petras; Scott B. Seibel; Annette M. Silvia; David M. George; Anne Hickman; Michelle L. Haven; Michael P. Lynch

2006-01-01

95

COX-2-dependent and COX-2-independent mode of action of celecoxib in human liver cancer cells.  

PubMed

Celecoxib (Celebrex((R)), Pfizer) is a selective cyclooxygenase-2 (COX-2) inhibitor with chemopreventive and antitumor effects. However, it is now well known that celecoxib has several COX-2-independent activities. To better understand COX-2-independent molecular mechanisms underlying the antitumor activity of celecoxib, we investigated the expression profile of the celecoxib-treated COX-2-positive (Huh7) and COX-2-negative (HepG2) liver cancer cell lines, using microarray analysis. Celecoxib treatment resulted in significantly altered expression levels of 240 and 403 transcripts in Huh7 and HepG2 cells, respectively. Confirmation of the microarray results was performed for selected genes by semiquantitative RT-PCR. A pathway/functional analysis of celecoxib-affected transcripts, using ingenuity pathway analysis and exploring biological association networks, revealed that celecoxib modulates expression of numerous genes involved in a variety of cellular processes, including cell death, cellular growth and proliferation, lipid metabolism, and energy turnover. Some of these processes were common for both HCC cell lines and seem to be coupled with NF-?B signaling, while others were cell-specific and possibly linked to the presence or the absence of COX-2 activity in the corresponding cell line. Many novel genes emerged from our analyses that were not previously reported to be affected by celecoxib. Further studies on selected celecoxib-responsive genes will establish if they may serve as potential molecular targets for more effective therapeutic strategies in HCC. PMID:21410330

Cervello, Melchiorre; Bachvarov, Dimcho; Cusimano, Antonella; Sardina, Francesca; Azzolina, Antonina; Lampiasi, Nadia; Giannitrapani, Lydia; McCubrey, James A; Montalto, Giuseppe

2011-06-01

96

Synthesis of novel 2-mercaptobenzoxazole based 1,2,3-triazoles as inhibitors of proinflammatory cytokines and suppressors of COX-2 gene expression.  

PubMed

A library of novel bis-heterocycles containing 2-mercaptobenzoxazole based 1,2,3-triazoles has been synthesized using click chemistry approach. The compound 4 exhibited the most potent in vivo anti-inflammatory activity with 66.66% and 61.11% inhibition in comparison to celecoxib which showed 72.22% and 65.55% inhibition after 3 h and 5 h respectively. The compounds 4 and 9 suppressed the COX-2 gene expression by 0.94 and 0.79 fold and exhibited a selective index (COX-1/COX-2) of 64.79 and 66.47 respectively in comparison to celecoxib (SI value of 75.56). The in silico molecular docking studies showed the interactions of these molecules with Tyr-59, Tyr-119 and Gly-121. When compared with the standard drug celecoxib, compounds 4, 5, 7, 9 and 16 did not cause any gastric ulceration. PMID:24836072

Haider, Saqlain; Alam, Mohammad Sarwar; Hamid, Hinna; Shafi, Syed; Dhulap, Abhijeet; Hussain, Firasat; Alam, Perwez; Umar, Sadiq; Pasha, M A Q; Bano, Sameena; Nazreen, Syed; Ali, Yakub; Kharbanda, Chetna

2014-06-23

97

Psoralidin, a dual inhibitor of COX-2 and 5-LOX, regulates ionizing radiation (IR)-induced pulmonary inflammation.  

PubMed

Radiotherapy is the most significant non-surgical cure for the elimination of tumor, however it is restricted by two major problems: radioresistance and normal tissue damage. Efficiency improvement on radiotherapy is demanded to achieve cancer treatment. We focused on radiation-induced normal cell damage, and are concerned about inflammation reported to act as a main limiting factor in the radiotherapy. Psoralidin, a coumestan derivative isolated from the seed of Psoralea corylifolia, has been studied for anti-cancer and anti-bacterial properties. However, little is known regarding its effects on IR-induced pulmonary inflammation. The aim of this study is to investigate mechanisms of IR-induced inflammation and to examine therapeutic mechanisms of psoralidin in human normal lung fibroblasts and mice. Here, we demonstrated that IR-induced ROS activated cyclooxygenases-2 (COX-2) and 5-lipoxygenase (5-LOX) pathway in HFL-1 and MRC-5 cells. Psoralidin inhibited the IR-induced COX-2 expression and PGE(2) production through regulation of PI3K/Akt and NF-?B pathway. Also, psoralidin blocked IR-induced LTB(4) production, and it was due to direct interaction of psoralidin and 5-lipoxygenase activating protein (FLAP) in 5-LOX pathway. IR-induced fibroblast migration was notably attenuated in the presence of psoralidin. Moreover, in vivo results from mouse lung indicate that psoralidin suppresses IR-induced expression of pro-inflammatory cytokines (TNF-?, TGF-?, IL-6 and IL-1 ?/?) and ICAM-1. Taken together, our findings reveal a regulatory mechanism of IR-induced pulmonary inflammation in human normal lung fibroblast and mice, and suggest that psoralidin may be useful as a potential lead compound for development of a better radiopreventive agent against radiation-induced normal tissue injury. PMID:21669192

Yang, Hee Jung; Youn, HyeSook; Seong, Ki Moon; Yun, Young Ju; Kim, Wanyeon; Kim, Young Ha; Lee, Ji Young; Kim, Cha Soon; Jin, Young-Woo; Youn, BuHyun

2011-09-01

98

Selective cyclo-oxygenase-2 inhibitors impair adipocyte differentiation through inhibition of the clonal expansion phase  

Microsoft Academic Search

Selective cyclo-oxygenase-2 (COX-2) inhibitors are nonsteroidal antiinflammatory drugs used in the man- agement of inflammatory diseases. We demonstrate here that inhibition of the COX-2 enzyme impairs adipocyte dif- ferentiation. The inhibition of adipogenesis occurs in the early clonal expansion phase. In particular, COX-2 inhibi- tion limits cell cycle reentry required before terminal adipo- cyte differentiation. This inhibition of adipogenesis is

Lluis Fajas; Stéphanie Miard; Michael R. Briggs; Johan Auwerx

2003-01-01

99

Distribution of constitutive (COX-1) and inducible (COX-2) cyclooxygenase in postviral human liver cirrhosis: a possible role for COX-2 in the pathogenesis of liver cirrhosis  

PubMed Central

Aims: Prostaglandins produced by the action of cyclooxygenases (COX) are important mediators of systemic vasodilatation and inflammation in liver cirrhosis. The aim of this study was to investigate the distribution of COX-1 and COX2 in postviral cirrhosis. Methods: The immunohistochemical expression of the constitutive (COX-1) and the inducible (COX-2) isoenzymes was investigated in 15 patients with cirrhosis after hepatitis B and C infection; three normal control livers were also analysed. Results: COX-2 was absent from normal liver but was highly expressed in cirrhosis, mainly in the inflammatory, sinusoidal, vascular endothelial, and biliary epithelial cells. Low amounts of COX-1 were expressed in both normal and cirrhotic livers, exclusively in sinusoidal and vascular endothelial cells, with no differences seen between normal and cirrhotic livers. Conclusions: COX-2 is overexpressed in liver cirrhosis, and possibly contributes to prostaglandin overproduction, which may be a major component of the inflammation and hyperdynamic circulation associated with cirrhosis. Because COX-2 is thought to contribute to tumour development, high COX-2 production could be a contributor to hepatocellular carcinoma development in cirrhosis. The finding of COX-2 and not COX-1 upregulation in cirrhosis could provide a possible new role for selective COX-2 inhibitors in reducing inflammation and minimising the occurrence of hepatocellular carcinoma in patients with cirrhosis.

Mohammed, N A; El-Aleem, S A; El-Hafiz, H A; McMahon, R F T

2004-01-01

100

Synergistic Effect of COX-2 Inhibitor on Paclitaxel-Induced Apoptosis in the Human Ovarian Cancer Cell Line OVCAR-3  

PubMed Central

Purpose Celecoxib, a highly selective cyclooxygenase-2 inhibitor, regulates apoptosis of several types of human cancer cells. The purpose of this study was to investigate whether celecoxib in combination with paclitaxel modulates apoptosis of ovarian cancer cells, and to identify the signal pathway by which celecoxib mediates apoptosis. Materials and Methods OVCAR-3 cells were exposed to paclitaxel (20 µM) in the absence or presence of celecoxib (10 µM). Cell viability was evaluated using a Cell Counting Kit-8 assay. Apoptosis was evaluated using Annexin-V/7-aminoactinomycin D staining and a cellular DNA fragmentation enzyme-linked immunosorbent assay. Caspase-3, -9, and cleavage of poly ADP-ribose polymerase (PARP) were determined by western blotting. Expression of nuclear factor-?B (NF-?B) and vascular endothelial growth factor (VEGF) and Akt activation were assessed using reverse transcriptase-polymerase chain reaction and western blotting. Results Celecoxib enhanced paclitaxel-induced growth inhibition of OVCAR-3 cells. Celecoxib significantly increased paclitaxel-induced apoptosis of OVCAR-3 cells. Pretreatment with celecoxib also increased activation of caspase-9, -3 and cleaved PARP following paclitaxel-treatment. Exposure of OVCAR-3 cells to celecoxib in combination with paclitaxel resulted in downregulation of NF-?B activation and VEGF expression. Furthermore, combining celecoxib and paclitaxel inhibited phosphorylation of Akt. Conclusion OVCAR-3 cells were sensitized to paclitaxel-induced apoptosis by celecoxib through downregulation of NF-?B and Akt activation, suggesting that celecoxib may work synergistically with paclitaxel to inhibit different targets and ultimately produce anticancer effects. Combining celecoxib with paclitaxel may prove beneficial in the clinical treatment of ovarian cancer.

Kim, Hee Jung; Yim, Ga Won; Nam, Eun Ji

2014-01-01

101

An analysis from clinico-epidemiological data of the principal adverse events from the COX2 selective NSAID, nimesulide, with particular reference to hepatic injury  

Microsoft Academic Search

The safety of the cyclo-oxygenase-2 (COX-2) selective NSAID, nimesulide, has been evaluated from information (a) in clinical\\u000a trials in osteoarthritis that have been performed in Europe as well as in earlier pilot studies that were performed in patients\\u000a with rheumatoid arthritis in the USA, and (b) in post-marketing studies (PMS) that have been performed by the manufacturer\\u000a since the introduction

K. D. Rainsford

1998-01-01

102

Treatment of feline mammary tumours using chemotherapy, surgery and a COX-2 inhibitor drug (meloxicam): a retrospective study of 23 cases (2002-2007)*.  

PubMed

The efficacy of a treatment combination of a COX-2 inhibitor (meloxicam), chemotherapy and surgery in 23 cats with histologically confirmed mammary gland adenocarcinoma was evaluated. All of the cases underwent an aggressive surgery with concurrent doxorubicin-based chemotherapy. Meloxicam was given orally starting the day after surgery and was continued indefinitely. Serum renal parameters were measured every 3-5 months. Three cats developed azotemia, whereas in four other renal parameters increased but remained within normal limit. The Kaplan-Meier median survival time was 460 days. The Kaplan-Meier median disease free interval was 269 days. The survival times are similar to other studies, not supporting the use of this treatment combination. Prospective studies with a higher number of cases are warranted to investigate the utility of this multimodality protocol for the treatment of feline mammary tumours. PMID:19891691

Borrego, J F; Cartagena, J C; Engel, J

2009-12-01

103

Detection of overexpressed COX2 in precancerous lesions of hamster pancreas and lungs by molecular imaging: implications for early diagnosis and prevention  

Microsoft Academic Search

The enzyme cyclooxygenase-2 (COX-2) is overexpressed in many cancers, cardiovascular disease, neurodegenerative disorders, and arthritis. Selective inhibitors of COX-2 have been developed as therapeutics or preventive agents for these diseases. However, recent reports have revealed a significant increase in cardiovascular mortality in long-term users of the COX-2 inhibitors Vioxx and Celebrex, emphasizing the need for noninvasive tests that allow the

George Kabalka; Gary Smith; Arjun Mereddy; Murthy Akula; Cekanova Maria

2006-01-01

104

Cyclooxygenase (COX)-1 activity precedes the COX-2 induction in A?-induced neuroinflammation.  

PubMed

Two different isoforms of cyclooxygenases, COX-1 and COX-2, are constitutively expressed under normal physiological conditions of the central nervous system, and accumulating data indicate that both isoforms may be involved in different pathological conditions. However, the distinct role of COX-1 and COX-2 and the probable interaction between them in neuroinflammatory conditions associated with Alzheimer's disease are conflicting issues. The aim of this study was to elucidate the comparable role of each COX isoform in neuroinflammatory response induced by ?-amyloid peptide (A?). Using histological and biochemical methods, 13 days after stereotaxic injection of A? into the rat prefrontal cortex, hippocampal neuroinflammation and neuronal injury were confirmed by increased expression of tumor necrosis factor-alpha (TNF-?) and COX-2, elevated levels of prostaglandin E2 (PGE2), astrogliosis, activation of caspase-3, and neuronal cell loss. Selective COX-1 or COX-2 inhibitors, SC560 and NS398, respectively, were chronically used to explore the role of COX-1 and COX-2. Treatment with either COX-1 or COX-2 selective inhibitor or their combination equally decreased the level of TNF-?, PGE2, and cleaved caspase-3 and attenuated astrogliosis and neuronal cell loss. Interestingly, treatment with COX-1 selective inhibitor or the combined COX inhibitors prevented the induction of COX-2. These results indicate that the activity of both isoforms is detrimental in neuroinflammatory conditions associated with A?, but COX-1 activity is necessary for COX-2 induction and COX-2 activity seems to be the main source of PGE2 increment. PMID:20549385

Dargahi, Leila; Nasiraei-Moghadam, Shiva; Abdi, Azadeh; Khalaj, Leila; Moradi, Fatemeh; Ahmadiani, Abolhassan

2011-09-01

105

Design, Synthesis and Biological Evaluation of New 5,5-Diarylhydantoin Derivatives as Selective Cyclooxygenase-2 Inhibitors  

PubMed Central

A new group of 5,5-diarylhydantoin derivatives bearing a methylsulfonyl COX-2 pharmacophore at the para position of the C-5 phenyl ring were designed and synthesized as selective COX-2 inhibitors. In vitro COX-1/COX-2 inhibition structure-activity relationships identified 5-[4-(methylsulfonyl)phenyl]-5-phenyl-hydantoin (4) as a highly potent and selective COX-2 inhibitor (COX-2 IC50 = 0.077 ?M; selectivity index > 1298). It was more selective than the reference drug celecoxib (COX-2 IC50 = 0.060 ?M; selectivity index = 405). A molecular modeling study where 4 was docked in the binding site of COX-2 indicated that the p-MeSO2 COX-2 pharmacophore group on the C-5 phenyl ring is oriented in the vicinity of the COX-2 secondary pocket. The results of this study showed that the type of substituent on the N-3 hydantoin ring substituent is important for COX-2 inhibitory activity.

Zarghi, Afshin; Javid, Farin Sattary; Ghodsi, Razieh; Dadrass, Orkideh G.; Daraei, Bahram; Hedayati, Mehdi

2011-01-01

106

Design, synthesis and biological evaluation of new 5,5-diarylhydantoin derivatives as selective cyclooxygenase-2 inhibitors.  

PubMed

A new group of 5,5-diarylhydantoin derivatives bearing a methylsulfonyl COX-2 pharmacophore at the para position of the C-5 phenyl ring were designed and synthesized as selective COX-2 inhibitors. In vitro COX-1/COX-2 inhibition structure-activity relationships identified 5-[4-(methylsulfonyl)phenyl]-5-phenyl-hydantoin (4) as a highly potent and selective COX-2 inhibitor (COX-2 IC(50) = 0.077 ?M; selectivity index > 1298). It was more selective than the reference drug celecoxib (COX-2 IC(50) = 0.060 ?M; selectivity index = 405). A molecular modeling study where 4 was docked in the binding site of COX-2 indicated that the p-MeSO(2) COX-2 pharmacophore group on the C-5 phenyl ring is oriented in the vicinity of the COX-2 secondary pocket. The results of this study showed that the type of substituent on the N-3 hydantoin ring substituent is important for COX-2 inhibitory activity. PMID:21886896

Zarghi, Afshin; Javid, Farin Sattary; Ghodsi, Razieh; Dadrass, Orkideh G; Daraei, Bahram; Hedayati, Mehdi

2011-09-01

107

Detection of overexpressed COX-2 in precancerous lesions of hamster pancreas and lungs by molecular imaging: implications for early diagnosis and prevention.  

PubMed

The enzyme cyclooxygenase-2 (COX-2) is overexpressed in many cancers, cardiovascular disease, neurodegenerative disorders, and arthritis. Selective inhibitors of COX-2 have been developed as therapeutics or preventive agents for these diseases. However, recent reports have revealed a significant increase in cardiovascular mortality in long-term users of the COX-2 inhibitors Vioxx and Celebrex, emphasizing the need for noninvasive tests that allow the identification of individuals whose COX-2 levels are overexpressed prior to assignment to treatment with these drugs. In this study, we have prepared a radioiodinated analogue of the selective COX-2 inhibitor celecoxib, and verified its binding to the COX-2 enzyme in vitro. Biodistribution studies in hamsters demonstrated significantly higher levels of radiotracer in animals treated with the tobacco carcinogen NNK in lung, pancreas, and liver. Assessment of COX-2 levels by whole-body planar nuclear imaging two hours after injection of the radiotracer was suggestive of a distinct increase in COX-2 in the pancreas and liver of a hamster treated for 10 weeks with NNK, in the lungs and liver of a second animal, and in the liver only, in two additional animals from the same treatment group. Immunostains showed selective overexpression of COX-2 in pre-neoplastic lesions of the pancreas and lungs in only those animals that showed tracer accumulation in these organs and in the livers of all NNK-treated hamsters. Immunostains for COX-1 yielded detectable reactions in the intestinal epithelium but not in pancreas, lungs, or liver, supporting the specificity of the tracer for COX-2. Our data provide proof of principle for the hypothesis that molecular imaging with radiolabeled COX-2 inhibitors can be used for the noninvasive monitoring of overexpressed COX-2 levels. PMID:16892400

Schuller, Hildegard M; Kabalka, George; Smith, Gary; Mereddy, Arjun; Akula, Murthy; Cekanova, Maria

2006-06-01

108

Acetaminophen (paracetamol) is a selective cyclooxygenase-2 inhibitor in man  

Microsoft Academic Search

For more than three decades, acetamin- ophen (INN, paracetamol) has been claimed to be devoid of significant inhibition of peripheral prosta- noids. Meanwhile, attempts to explain its action by inhibition of a central cyclooxygenase (COX)-3 have been rejected. The fact that acetaminophen acts func- tionally as a selective COX-2 inhibitor led us to investi- gate the hypothesis of whether it

Burkhard Hinz; Olga Cheremina; Kay Brune

2007-01-01

109

Transgenic Insulin-like Growth Factor-1 stimulates activation of COX-2 signaling in mammary glands  

PubMed Central

Studies show that elevated IGF-1 levels are associated with an increased risk of breast cancer; however, mechanisms through which IGF-1 promotes mammary tumorigenesis in vivo have not been fully elucidated. To assess the possible involvement of COX-2 signaling in the protumorigenic effects of IGF-1 in mammary glands, we used the unique BK5.IGF-1 mouse model in which transgenic (Tg) mice have significantly increased incidence of spontaneous and DMBA–induced mammary cancer compared to wild type (WT) littermates. Studies revealed that COX-2 expression was significantly increased in Tg mammary glands and tumors, compared to age-matched WTs. Consistent with this, PGE2 levels were also increased in Tg mammary glands. Analysis of expression of the EP receptors that mediate the effects of PGE2 showed that among the four G-protein-coupled receptors, EP3 expression was elevated in Tg glands. Up-regulation of the COX-2/PGE2/EP3 pathway was accompanied by increased expression of VEGF and a striking enhancement of angiogenesis in IGF-1 Tg mammary glands. Treatment with celecoxib, a selective COX-2 inhibitor, caused a 45% reduction in mammary PGE2 levels, attenuated the influx of mast cells and reduced vascularization in Tg glands. These findings indicate that the COX-2/PGE2/EP3 signaling pathway is involved in IGF-1–stimulated mammary tumorigenesis and that COX-2selective inhibitors may be useful in the prevention or treatment of breast cancer associated with elevated IGF-1 levels in humans.

Tian, Jie; Lambertz, Isabel; Berton, Thomas R.; Rundhaug, Joyce E.; Kiguchi, Kaoru; Shirley, Stephanie H.; DiGiovanni, John; Conti, Claudio J.; Fischer, Susan M.; Fuchs-Young, Robin

2011-01-01

110

Renal Effects of Nabumetone, a COX2 Antagonist: Impairment of Function in Isolated Perfused Rat Kidneys Contrasts with Preserved Renal Function in vivo  

Microsoft Academic Search

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

James Reichman; Shlomo Cohen; Marina Goldfarb; Ahuva Shina; Seymour Rosen; Mayer Brezis; Fanny Karmeli; Samuel N. Heyman

2001-01-01

111

Co-administration of acetyl-11-keto-beta-boswellic acid, a specific 5-lipoxygenase inhibitor, potentiates the protective effect of COX-2 inhibitors in kainic acid-induced neurotoxicity in mice.  

PubMed

Cyclooxygenase (COX) and lipoxygenase (LOX) are responsible for the metabolism of arachidonic acid into inflammatory metabolites, prostaglandins and leukotrienes, respectively. The upregulation of these enzymes in the central nervous system has been demonstrated to be responsible for the increased neuronal vulnerability to degeneration. Kainic acid, a glutamate receptor agonist and responsible for neuronal excitotoxicity and oxidative damage via different mechanisms, is capable of stimulating mRNA of both COX-2 and 5-LOX in the brain. The present study was designed to study the effects of COX inhibitors (indomethacin, nimesulide, rofecoxib) and a 5-LOX inhibitor (acetyl-11-keto-beta-boswellic acid; AKBA) and the combination of these inhibitors (dual inhibition) on kainic acid induced excitotoxicity and oxidative and nitrosative damage in mice. The results from the present study indicated that AKBA, indomethacin, and nimesulide per se did not produce any change in the behavioural parameters after kainic acid administration; however, rofecoxib per seproduced a significant increase in the latency of clonic (seizure-like) movement and a decrease in mortality rate as compared with kainic acid treated animals. In combination studies AKBA, rofecoxib, and nimesulide produced a more pronounced effect than either of these drugs alone. Further, the effect of AKBA combined with rofecoxib was significantly more marked when compared with AKBA combined with nimesulide. Besides this, identical results were found for the effect of these agents and their combination against oxidative damage induced by kainic acid. These findings indicate the potential role of COX-2 inhibitors and also their combination with the 5-LOX inhibitor in kainic acid induced excitotoxicity and oxidative damage by virtue of their antioxidant effect and suggest the need for the development of dual inhibitors for the treatment of neuronal excitotoxicity. PMID:17139192

Bishnoi, Mahendra; Patil, C S; Kumar, Anil; Kulkarni, Shrinivas K

2007-01-01

112

Design, Synthesis and Biological Evaluation of 5-Oxo-1,4,5,6,7,8 Hexahydroquinoline Derivatives as Selective Cyclooxygenase-2 Inhibitors  

PubMed Central

A group of regioisomeric 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives possessing a COX-2 SO2Me pharmacophore at the para position of the C-2 or C-4 phenyl ring, in conjunction with a C-4 or C-2 phenyl (4-H) or substituted-phenyl ring (4-F,4-Cl,4-Br,4-OMe,4-Me, 4-NO2), were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. These target 5-oxo-1,4,5,6,7,8 hexahydroquinolines were synthesized via a Hansch condensation reaction. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 7,8-dihydro- 7,7-dimethyl-2-(4-methoxyphenyl)-4-(4-(methylsulfonyl)phenyl)quinolin-5(1H,4H,6H)- one (9c) as a potent COX-2 inhibitor (IC50 = 0.17 M) with a high COX-2 selectivity index (S.I. = 97.6) comparable to the reference drug celecoxib (COX-2 IC50 = 0.05 mM; COX-2 S.I= 405). A molecular modeling study where 9c was docked in active site of COX-2 showed that the p-SO2Me substituent on the C-2 phenyl ring is inserted into the secondary COX-2 binding site. The structure activity data acquired indicate that the position of the COX-2 SO2Me pharmacophore and type of substituent are important for COX-2 inhibitory activity.

Zarghi, Afshin; Sabakhi, Iman; Topuzyan, Vigen; Hajimahdi, Zahra; Daraie, Bahram

2014-01-01

113

Design, synthesis and biological evaluation of 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives as selective cyclooxygenase-2 inhibitors.  

PubMed

A group of regioisomeric 5-oxo-1,4,5,6,7,8 hexahydroquinoline derivatives possessing a COX-2 SO2Me pharmacophore at the para position of the C-2 or C-4 phenyl ring, in conjunction with a C-4 or C-2 phenyl (4-H) or substituted-phenyl ring (4-F,4-Cl,4-Br,4-OMe,4-Me, 4-NO2), were designed for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors. These target 5-oxo-1,4,5,6,7,8 hexahydroquinolines were synthesized via a Hansch condensation reaction. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 7,8-dihydro- 7,7-dimethyl-2-(4-methoxyphenyl)-4-(4-(methylsulfonyl)phenyl)quinolin-5(1H,4H,6H)- one (9c) as a potent COX-2 inhibitor (IC50 = 0.17 M) with a high COX-2 selectivity index (S.I. = 97.6) comparable to the reference drug celecoxib (COX-2 IC50 = 0.05 mM; COX-2 S.I= 405). A molecular modeling study where 9c was docked in active site of COX-2 showed that the p-SO2Me substituent on the C-2 phenyl ring is inserted into the secondary COX-2 binding site. The structure activity data acquired indicate that the position of the COX-2 SO2Me pharmacophore and type of substituent are important for COX-2 inhibitory activity. PMID:24711830

Zarghi, Afshin; Sabakhi, Iman; Topuzyan, Vigen; Hajimahdi, Zahra; Daraie, Bahram

2014-01-01

114

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

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. PMID:24083950

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

115

Pharmacology of a selective cyclooxygenase-2 inhibitor, HN-56249: a novel compound exhibiting a marked preference for the human enzyme in intact cells.  

PubMed

HN-56249 (3-(2,4-dichlorothiophenoxy)-4-methylsulfonylamino-benzenesu lfonamide), a highly selective cyclooxygenase (COX)-2 inhibitor, is the prototype of a novel series of COX inhibitors comprising bicyclic arylethersulfonamides; of this series HN-56249 is the most potent and selective human COX-2 inhibitor. HN-56249 inhibited platelet aggregation as a measure of COX-1 activity only moderately (IC50 26.5+/-1.7 microM). In LPS-stimulated monocytic cells the release of prostaglandin (PG) F1alpha as a measure of COX-2 was markedly inhibited (IC50 0.027+/-0.001 microM). Thus, HN-56249 showed an approximately 1000-fold selectivity for COX-2 in intact cells. In whole blood assays HN-56249 showed a potent inhibitory activity for COX-2 (IC50 0.78+/-0.37 microM) only. COX-1 was only weakly inhibited (IC50 867+/-181 microM). Hence, HN-56249 exhibited a greater than 1000-fold selectivity for whole blood COX-2. HN-56249 surpassed the COX-2 selectivities of the COX-2 selective inhibitors 3-cyclohexyloxy-4-methylsulfonylamino-nitrobenzene (NS-398) and 6-(2,4-difluorophenoxy)-5-methyl-sulfonylamino-1-indanone (flosulide) in the intact cell assays by eight- and threefold, respectively, and in the whole blood assays by approximately 40-fold. Following i.v. administration HN-56249 inhibited carrageenan-induced rat paw oedema only moderately (ID50 26.2+/-5.7 mg/kg, mean +/- SEM), approximately tenfold less potent than indomethacin (ID50 2.1+/-0.2 mg/kg, mean +/- SEM). After oral administration HN-56249 reversed thermal hyperalgesia in the carrageenan-induced rat paw oedema test, however, some 30-fold less potently than diclofenac. Comparing the inhibitory potency of HN-56249 against human COX-2 with that against murine COX-2 in intact cells revealed a 300-fold selectivity for the human enzyme. Similar effects were observed with other COX-2-selective arylethersulfonamides. In contrast, non-COX-2-selective arylethersulfonamides, including a highly selective COX-1 inhibitor, inhibited human and murine COX-2 approximately equipotently. In conclusion, HN-56249 is a novel potent and highly selective COX-2 inhibitor with a marked preference for the human COX-2 enzyme in vitro. Despite excellent bioavailability and the long plasma half-life of HN-56249, anti-inflammatory effects in rodents were only moderate. We suggest these differing in vitro-in vivo effects observed could be due to significant inflammatory prostaglandin synthesis by COX-1, or to the genetic differences between human and rodent COX-2, or to both. PMID:10763850

Berg, J; Fellier, H; Christoph, T; Kremminger, P; Hartmann, M; Blaschke, H; Rovensky, F; Towart, R; Stimmeder, D

2000-04-01

116

The COX-2/PGI2 Receptor Axis Plays an Obligatory Role in Mediating the Cardioprotection Conferred by the Late Phase of Ischemic Preconditioning  

PubMed Central

Background Pharmacologic studies with cyclooxygenase-2 (COX-2) inhibitors suggest that the late phase of ischemic preconditioning (PC) is mediated by COX-2. However, nonspecific effects of COX-2 inhibitors cannot be ruled out, and the selectivity of these inhibitors for COX-2 vs. COX-1 is only relative. Furthermore, the specific prostaglandin (PG) receptors responsible for the salubrious actions of COX-2-derived prostanoids remain unclear. Objective To determine the role of COX-2 and prostacyclin receptor (IP) in late PC by gene deletion. Methods COX-2 knockout (KO) mice (COX-2?/?), prostacyclin receptor KO (IP?/?) mice, and respective wildtype (WT, COX-2+/+ and IP+/+) mice underwent sham surgery or PC with six 4-min coronary occlusion (O)/4-min R cycles 24 h before a 30-min O/24 h R. Results There were no significant differences in infarct size (IS) between non-preconditioned (non-PC) COX-2+/+, COX-2?/?, IP+/+, and IP?/? mice, indicating that neither COX-2 nor IP modulates IS in the absence of PC. When COX-2?/? or IP?/? mice were preconditioned, IS was not reduced, indicating that the protection of late PC was completely abrogated by deletion of either the COX-2 or the IP gene. Administration of the IP selective antagonist, RO3244794 to C57BL6/J (B6) mice 30 min prior to the 30-min O had no effect on IS. When B6 mice were preconditioned 24 h prior to the 30-min O, IS was markedly reduced; however, the protection of late PC was completely abrogated by pretreatment of RO3244794. Conclusions This is the first study to demonstrate that targeted disruption of the COX-2 gene completely abrogates the infarct-sparing effect of late PC, and that the IP, downstream of the COX-2/prostanoid pathway, is a key mediator of the late PC. These results provide unequivocal molecular genetic evidence for an essential role of the COX-2/PGI2 receptor axis in the cardioprotection afforded by the late PC.

Guo, Yiru; Tukaye, Deepali Nivas; Wu, Wen-Jian; Zhu, Xiaoping; Book, Michael; Tan, Wei; Jones, Steven P.; Rokosh, Gregg; Narumiya, Shuh; Li, Qianhong; Bolli, Roberto

2012-01-01

117

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

PubMed

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. PMID:24969217

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

2014-08-01

118

Novel 1-[4-(Aminosulfonyl)phenyl]-1H-1,2,4-triazole derivatives with remarkable selective COX-2 inhibition: Design, synthesis, molecular docking, anti-inflammatory and ulcerogenicity studies.  

PubMed

A novel series of 1,2,4-triazole derivatives were synthesized and confirmed with different spectroscopic techniques. The prepared compounds exhibited remarkable anti-inflammatory activity comparable to that of indomethacin and celecoxib after 3 h. The tested compounds exhibited very low incidence of gastric ulceration compared to indomethacin. Most of the newly developed compounds showed excellent selectivity towards human COX-2 with selectivity indices (COX-1 IC50/COX-2 IC50) ranged from 62.5 to 2127. Docking studies results revealed that the highly selective tested compounds 6h and 6j showed lower CDOCKER energies, which means that they require less energy for proper interaction with the enzyme. The additional H-bonds with the oxygen of the amide and/or H of NH of the amide with the amino acid residues may be responsible for the higher binding affinity of this group of compounds towards COX-2. PMID:24983538

Abuo-Rahma, Gamal El-Din A A; Abdel-Aziz, Mohamed; Farag, Nahla A; Kaoud, Tamer S

2014-08-18

119

Increased dietary sodium induces COX2 expression by activating NF?B in renal medullary interstitial cells.  

PubMed

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 NF?B 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 NF?B reporter transgenic mice, we observed a sevenfold increase of luciferase activity in the renal medulla of the NF?B-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 NF?B-EGFP reporter mice following high salt diet. Treating high salt diet-fed C57Bl/6 J mice with selective I?B 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 NF?B plays an important role in mediating renal medullary COX2 expression and promoting renal PGE2 synthesis in response to increased dietary sodium. PMID:23900806

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

2014-02-01

120

The influence of Cox-2 and bioactive lipids on hematological cancersa  

PubMed Central

Inflammation is implicated in the progression of multiple types of cancers including lung, colorectal, breast and hematological malignancies. Cyclooxygenases (Cox) -1 and -2 are important enzymes involved in the regulation of inflammation. Elevated Cox-2 expression is associated with a poor cancer prognosis. Hematological malignancies, which are among the top 10 most predominant cancers in the USA, express high levels of Cox-2. Current therapeutic approaches against hematological malignances are insufficient as many patients develop resistance or relapse. Therefore, targeting Cox-2 holds promise as a therapeutic approach to treat hematological malignancies. NSAIDs and Cox-2 selective inhibitors are anti-inflammatory drugs that decrease prostaglandin and thromboxane production while promoting the synthesis of specialized proresolving mediators. Here, we review the evidence regarding the applicability of NSAIDs, such as aspirin, as well as Cox-2 specific inhibitors, to treat hematological malignancies. Furthermore, we discuss how FDA-approved Cox inhibitors can be used as anti-cancer drugs alone or in combination with existing chemotherapeutic treatments.

Ramon, Sesquile; Woeller, Collynn F.; Phipps, Richard P.

2014-01-01

121

Cardiovascular Thromboembolic Adverse Effects Associated with Cyclooxygenase2 Selective Inhibitors and Nonselective Antiinflammatory Drugs  

Microsoft Academic Search

BACKGROUND: Concerns of increased cardiovascular (CV) thromboembolic adverse effects from nonsteroidal antiinflammatory drugs (NSAIDs, both nonselective (NS)-NSAIDs and cyclooxygenase (COX)-2 selective inhibitors) have prevented their use despite numerous benefits. METHODS: In this descriptive review, we critically examine the randomized, active- and placebo-controlled studies, observational trials, and meta-analyses evaluating the CV adverse effects associated with long-term and short-term use of COX-2

Girish P. Joshi; Ralph Gertler; Ruth Fricker

2007-01-01

122

'Bridged' stilbene derivatives as selective cyclooxygenase-1 inhibitors.  

PubMed

Resveratrol ((E)-3,4',5-trihydroxy-stilbene), a phytoalexin found in various plants, shows non-selective cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibition. In order to find more selective COX inhibitors a series of bridged stilbene derivatives was synthesized and evaluated for their ability to inhibit both COX-1 and COX-2 in vitro. The compounds showed a high rate of COX-1 inhibition with the most potent compounds exhibiting submicromolar IC(50) values and high selectivity indices. A prediction model for COX-inhibiting activity was also developed using the classical LIE approach resulting in consistent docking data for our molecule sample. Phenyl substituted 1,2-dihydronaphthalene derivatives and 1H-indene derivatives therefore represent a novel class of highly selective COX-1 inhibitors and land promising candidates for in vivo studies. PMID:17604631

Handler, Norbert; Brunhofer, Gerda; Studenik, Christian; Leisser, Klaus; Jaeger, Walter; Parth, Stephanie; Erker, Thomas

2007-09-15

123

Synthesis, biological evaluation, molecular docking and theoretical evaluation of ADMET properties of nepodin and chrysophanol derivatives as potential cyclooxygenase (COX-1, COX-2) inhibitors.  

PubMed

Nepodin and chrysophanol, isolated from Rumex nepalensis roots, showed significant cyclooxygenase (COX) inhibitory activity. To further optimize these lead molecules and study structure activity relationship (SAR), eighteen derivatives of nepodin and nine derivatives of chrysophanol were synthesized and evaluated for COX-1 and COX-2 inhibitory potential. Among the synthesized compounds, four nepodin (1f, 1g, 1h and 1i) and three chrysophanol (2e, 2f and 2h) derivatives displayed more pronounced COX-2 inhibition than their respective lead molecule. Further, compounds 1f, 1g, 2e and 2h exhibited better anti-inflammatory activity than ibuprofen in carrageenan-induced rat paw edema assay. Taking into account the in vitro and in vivo results, molecular docking and in silico prediction of ADMET properties of compounds were carried out respectively. PMID:24763362

Grover, Jagdeep; Kumar, Vivek; Singh, Vikram; Bairwa, Khemraj; Sobhia, M Elizabeth; Jachak, Sanjay M

2014-06-10

124

COX-2 signaling and cancer: new players in old arena.  

PubMed

Cancer is a leading cause of death worldwide. The expression of COX-2 and prostaglandins has not only been associated with various types of cancer but is also directly proportional to their aggressiveness including metastasis. Thus, inhibition of COX-2 activity has been one of the preferred targets for cancer reduction. Broad spectrum inhibition of all forms of COX (using NSAIDs) is associated with various side effects ranging from gastric ulceration to renal problems. Even specific COX-2 inhibitors (COXIBs) are associated with side effects like myocardial infarction. Alternative strategies including siRNA technology are also not very victorious due to their off-target associated problems. Thus, there is an urgent need for the development of strategies where COX-2 activity may be reduced without inducing any side effects. One of the approaches for designing novel inhibitors may be to target various molecules downstream of COX-2. In this review, we have tried to cover the basic biology of COX-2 and its association with different types of cancer. Various generations of COX-2 inhibitors have been covered with their merits and demerits. Possible exploitation of novel targets like EP receptors, mPGES and various other downstream molecules which can be utilized for a better COX-2 signaling inhibition and thus efficient cancer reduction with minimal side effects has been discussed. PMID:24467618

Misra, Shashank; Sharma, Kulbhushan

2014-03-01

125

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

SciTech Connect

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.

Zhu, Yingting, E-mail: yitizhu@yahoo.com [University of Arizona Arizona Cancer Center Tissue Tech Inc, 7000 SW 97th Avenue Suite 212, Miami, FL 33173 (United States) [University of Arizona Arizona Cancer Center Tissue Tech Inc, 7000 SW 97th Avenue Suite 212, Miami, FL 33173 (United States); Tissue Tech Inc, Miami, FL 33173 (United States); Zhu, Min; Lance, Peter [University of Arizona Arizona Cancer Center Tissue Tech Inc, 7000 SW 97th Avenue Suite 212, Miami, FL 33173 (United States)] [University of Arizona Arizona Cancer Center Tissue Tech Inc, 7000 SW 97th Avenue Suite 212, Miami, FL 33173 (United States)

2012-11-15

126

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

PubMed Central

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.

Sokolowski, Grzegorz; Baldys-Waligorska, Agata; Trofimiuk, Malgorzata; Adamek, Dariusz; Hubalewska-Dydejczyk, Alicja; Golkowski, Filip

2012-01-01

127

The Adverse Effect of Selective Cyclooxygenase-2 Inhibitor on Random Skin Flap Survival in Rats  

PubMed Central

Background Cyclooxygenase-2(COX-2) inhibitors provide desired analgesic effects after injury or surgery, but evidences suggested they also attenuate wound healing. The study is to investigate the effect of COX-2 inhibitor on random skin flap survival. Methods The McFarlane flap model was established in 40 rats and evaluated within two groups, each group gave the same volume of Parecoxib and saline injection for 7 days. The necrotic area of the flap was measured, the specimens of the flap were stained with haematoxylin-eosin(HE) for histologic analysis. Immunohistochemical staining was performed to analyse the level of VEGF and COX-2 . Results 7 days after operation, the flap necrotic area ratio in study group (66.65±2.81)% was significantly enlarged than that of the control group(48.81±2.33)%(P <0.01). Histological analysis demonstrated angiogenesis with mean vessel density per mm2 being lower in study group (15.4±4.4) than in control group (27.2±4.1) (P <0.05). To evaluate the expression of COX-2 and VEGF protein in the intermediate area II in the two groups by immunohistochemistry test .The expression of COX-2 in study group was (1022.45±153.1), and in control group was (2638.05±132.2) (P <0.01). The expression of VEGF in the study and control groups were (2779.45±472.0) vs (4938.05±123.6)(P <0.01).In the COX-2 inhibitor group, the expressions of COX-2 and VEGF protein were remarkably down-regulated as compared with the control group. Conclusion Selective COX-2 inhibitor had adverse effect on random skin flap survival. Suppression of neovascularization induced by low level of VEGF was supposed to be the biological mechanism.

Ren, Haiyong; Lin, Dingsheng; Mou, Zhenyu; Dong, Pu

2013-01-01

128

COX-2 active agents in the chemoprevention of colorectal cancer.  

PubMed

Chemopreventive strategies for colorectal cancer (CRC) have been extensively studied to prevent the recurrence of adenomas and/or delay their development in the gastrointestinal tract. The non-steroidal anti-inflammatory drugs (NSAIDs) and selective cyclooxygenase (COX)-2 inhibitors have been proven as promising and the most attractive candidates for CRC clinical chemoprevention. The preventive efficacy of these agents is supported by a large number of animal and epidemiological studies which have clearly demonstrated that NSAID consumption prevents adenoma formation and decreases the incidence of, and mortality from CRC. On the basis of these studies, aspirin chemoprevention may be effective in preventing CRC within the general population, while aspirin and celecoxib may be effective in preventing adenomas in patients after polypectomy. Nevertheless, the consumption of NSAID and COX-2 inhibitors is not toxic free. Well-known serious adverse events to the gastrointestinal, renal and cardiovascular systems have been reported. These reports have led to some promising studies related to the use of lower doses and in combination with other chemopreventive agents and shown efficacy. In the intriguing jigsaw puzzle of cancer prevention, we now have a definite positive answer for the basic question "if", but several other parts of the equation-proper patient selection, the ultimate drug, optimal dosage and duration are still missing. PMID:22893201

Kraus, Sarah; Naumov, Inna; Arber, Nadir

2013-01-01

129

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

PubMed

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 2days post fertilization (dpf) showed close similarity to that for conventional pericardial edema at 3dpf. Precardiac edema caused by TCDD was reduced by morpholino knockdown of AHR2 and ARNT1, as well as by an antioxidant (ascorbic acid). A selective inhibitor of cyclooxygenase type 2 (COX2), NS398, also markedly inhibited TCDD-induced precardiac edema. A thromboxane receptor (TP) antagonist, ICI-192,605 almost abolished TCDD-induced precardiac edema and this effect was canceled by U46619, a TP agonist, which was not influential in the action of TCDD by itself. Knockdown of COX2b and thromboxane A synthase 1 (TBXS), but not COX2a, strongly reduced TCDD-induced precardiac edema. Knockdown of COX2b was without effect on mesencephalic circulation failure caused by TCDD. The edema by TCDD was also inhibited by knockdown of c-mpl, a thrombopoietin receptor necessary for thromobocyte production. Finally, induction of COX2b, but not COX2a, by TCDD was seen in eleutheroembryos at 3dpf. These results suggest a role of the COX2b-thromboxane pathway in precardiac edema formation following TCDD exposure in developing zebrafish. PMID:24858302

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

2014-09-01

130

Urinary tract obstruction induces transient accumulation of COX-2-derived prostanoids in kidney tissue  

PubMed Central

Inhibitors of cyclooxygenase (COX)-2 prevent suppression of aquaporin-2 and reduce polyuria in the acute phase after release of bilateral ureteral obstruction (BUO). We hypothesized that BUO leads to COX-2-mediated local accumulation of prostanoids in inner medulla (IM) tissue. To test this, rats were subjected to BUO and treated with selective COX-1 or COX-2 inhibitors. Tissue was examined at 2, 6, 12, and 24 h after BUO. COX-2 protein abundance increased in IM 12 and 24 h after onset of BUO but did not change in cortex. COX-1 did not change at any time points in any region. A full profile of all five primary prostanoids was obtained by mass spectrometric determination of PGE2, PGF2?, 6-keto-PGF1?, PGD2, and thromboxane (Tx) B2 concentrations in kidney cortex/outer medulla and IM fractions. IM concentration of PGE2, 6-keto-PGF1?, and PGF2? was increased at 6 h BUO, and PGE2 and PGF2? increased further at 12 h BUO. TxB2 increased after 12 h BUO. 6-keto-PGF1? remained significantly increased after 24 h BUO. The COX-2 inhibitor parecoxib lowered IM PGE2, TxB2, 6-keto-PGF1?, and PGF2? below vehicle-treated BUO and sham rats at 6, 12 and, 24 h BUO. The COX-1 inhibitor SC-560 lowered PGE2, PGF2?, and PGD2 in IM compared with untreated 12 h BUO, but levels remained significantly above sham. In cortex tissue, PGE2 and 6-keto-PGF1? concentrations were elevated at 6 h only. In conclusion, COX-2 activity contributes to the transient increase in prostacyclin metabolite 6-keto-PGF1? and TxB2 concentration in the kidney IM, and COX-2 is the predominant isoform that is responsible for accumulation of PGE2 and PGF2? with minor, but significant, contributions from COX-1. PGD2 synthesis is mediated exclusively by COX-1. In BUO, therapeutic interventions aimed at the COX-prostanoid pathway should target primarily COX-2.

N?rregaard, Rikke; Jensen, Boye L; Topcu, Sukru Oguzkan; Wang, Guixian; Schweer, Horst; Nielsen, S?ren

2010-01-01

131

Suppression of Intestinal Polyposis in Apc ?716 Knockout Mice by Inhibition of Cyclooxygenase 2 (COX2)  

Microsoft Academic Search

Two cyclooxygenase isozymes catalyze conversion of arachidonic acid to prostaglandin H2: constitutive COX-1 and inducible COX-2. To assess the role of COX-2 in colorectal tumorigenisis, we determined the effects of COX-2 gene (Ptgs2) knockouts and a novel COX-2 inhibitor on Apc?716knockout mice, a model of human familial adenomatous polyposis. A Ptgs2null mutation reduced the number and size of the intestinal

Masanobu Oshima; Joseph E Dinchuk; Stacia L Kargman; Hiroko Oshima; Bruno Hancock; Elizabeth Kwong; James M Trzaskos; Jilly F Evans; Makoto M Taketo

1996-01-01

132

Genetic deletion of COX-2 prevents increased renin expression in response to ACE inhibition.  

PubMed

Cyclooxygenase-2 (COX-2) is expressed in macula densa (MD) and surrounding cortical thick ascending limb of the loop of Henle (cTALH) and is involved in regulation of renin production. We and others have previously found that selective COX-2 inhibitors can inhibit renal renin production (Cheng HF, Wang JL, Zhang MZ, Miyazaki Y, Ichikawa I, McKanna JA, and Harris RC. J Clin Invest 103: 953-961, 1999; Harding P, Sigmon DH, Alfie ME, Huang PL, Fishman MC, Beierwaltes WH, and Carretero OA. Hypertension 29: 297-302, 1997; Traynor TR, Smart A, Briggs JP, and Schnermann J. Am J Physiol Renal Physiol 277: F706-F710, 1999; Wang JL, Cheng HF, and Harris RC. Hypertension 34: 96-101, 1999). In the present studies, we utilized mice with genetic deletions of the COX-2 gene in order to investigate further the potential role of COX-2 in mediation of the renin-angiotensin system (RAS). Age-matched wild-type (+/+), heterozygotes (+/-), and homozygous null mice (-/-) were administered the angiotensin-converting enzyme inhibitor (ACEI), captopril, for 7 days. ACEI failed to significantly increase plasma renin activity, renal renin mRNA expression, and renal renin activity in (-/-) mice. ACEI increased the number of cells expressing immunoreactive renin in the (+/+) mice both by inducing more juxtaglomerular cells to express immunoreactive renin and by recruiting additional renin-expressing cells in the more proximal afferent arteriole. In contrast, there was minimal recruitment of renin-expressing cells in the more proximal afferent arteriole of the -/- mice. In summary, these results indicate that ACEI-mediated increases in renal renin production were defective in COX-2 knockout (K/O) mice and provide further indication that MD COX-2 is an important mediator of the renin-angiotensin system. PMID:11181406

Cheng, H F; Wang, J L; Zhang, M Z; Wang, S W; McKanna, J A; Harris, R C

2001-03-01

133

Effects of Selective Cyclooxygenase Inhibitors on Ischemia\\/Reperfusion-Induced Hepatic Microcirculatory Dysfunction in Mice  

Microsoft Academic Search

We examined the effects of selective cyclooxygenase (COX) inhibition on hepatic warm ischemia\\/reperfusion (I\\/R) injury in mice. A selective COX-1 inhibitor, SC-560, selective COX-2 inhibitors, NS-398 and celecoxib, and indomethacin were administered 30 min before ischemia. Four hours after reperfusion, an in vivo microscopic study showed that I\\/R caused significant accumulation of leukocytes adhering to the hepatic microvessels and nonperfused

Y. Ito; H. Katagiri; K. Ishii; A. Kakita; I. Hayashi; M. Majima

2003-01-01

134

Cancer chemoprevention by cyclooxygenase 2 (COX-2) blockade: results of case control studies.  

PubMed

Significant use of selective cyclooxygenase-2 (COX-2) blocking agents prescribed for the treatment of arthritis during 1999 to 2005 facilitates epidemiologic investigations to illuminate their chemopreventive effects against human cancer. We therefore conducted a set of case control studies of selective COX-2 blocking agents to determine their chemopreventive potential for the four major cancers: breast, prostate, colon, and lung. Newly diagnosed cases (323 breast cancer patients, 229 prostate cancer patients, 326 colon cancer patients, and 486 lung cancer patients) were ascertained during 2002 to September 30, 2004, at The James Cancer Hospital and Solove Research Institute, The Ohio State University Medical Center, Columbus, Ohio. All cases of invasive cancer were confirmed by examination of the pathology report. Healthy controls without cancer were ascertained from hospital screening clinics during the same time period. Controls were frequency matched at a rate of 2:1 to the cases by age, gender, and county of residence. We collected information on type, frequency, and duration of use of selective COX-2 inhibitors and nonselective nonsteroidal anti-inflammatory drugs (NSAIDs). Other potentially important risk factors (smoking, drinking, body mass, medical history, blood pressure and cholesterol medications, family history of cancer, occupational history, and reproductive history for women) were also recorded for each subject. Estimates of odds ratios were obtained with adjustment for age and other potential confounders using logistic regression analysis. Use of selective COX-2 inhibitors resulted in a significant risk reduction for each type of cancer (71% for breast cancer, 55% for prostate cancer, 70% for colon cancer, and 79% for lung cancer) and an overall 68% risk reduction for all four cancers. This investigation demonstrates that COX-2 blocking agents have strong potential for the chemoprevention of cancers of the breast, prostate, colon and lung. PMID:17612052

Harris, Randall E; Beebe-Donk, Joanne; Alshafie, Galal A

2007-01-01

135

25-Hydroxycholesterol exerts both a cox-2-dependent transient proliferative effect and cox-2-independent cytotoxic effect on bovine endothelial cells in a time- and cell-type-dependent manner  

PubMed Central

Background 25-hydroxycholesterol (25-OHC) is a product of oxidation of dietary cholesterol present in human plasma. 25-OHC and other oxidized forms of cholesterol are implicated in modulating inflammatory responses involved in development of atherosclerosis and colon carcinogenesis. Methods Primary lymphatic, venous and arterial endothelial cells isolated from bovine mesentery (bmLEC, bmVEC, bmAEC) were treated with 25-OHC and tested for several different cellular parameters. Results We found 25-OHC to be a potent inducer of cyclooxygenase-2 (Cox-2, prostaglandin G-H synthase-2) expression in bovine mesenteric lymphatic, venous, and arterial endothelial cells. The induction of Cox-2 expression in endothelial cells by 25-OHC led to an initial increase in cellular proliferation that was inhibited by the Cox-2 selective inhibitor celecoxib (Celebrex). Prolonged exposure to 25-OHC was cytotoxic. Furthermore, endothelial cells induced to express Cox-2 by 25-OHC were more sensitive to the effects of the Cox-2 selective inhibitor celecoxib (Celebrex). These results suggest that some effects of 25-OHC on cells may be dependent on Cox-2 enzymatic activity. Conclusions Cox-2 dependent elevating effects of 25-OHC on endothelial cell proliferation was transient. Prolonged exposure to 25-OHC caused cell death and enhanced celecoxib-induced cell death in a cell-type dependent manner. The lack of uniform response by the three endothelial cell types examined suggests that our model system of primary cultures of bmLECs, bmVECs, and bmAECs may aid the evaluation of celecoxib in inhibiting proliferation of different types of tumour-associated endothelial cells.

2010-01-01

136

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

PubMed

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 (?-MSH)-induced melanin production. In addition, ?-MSH-induced COX-2 expression in both scrambled siRNA-transfected and COX-2 siRNA-transfected melanocytes was greater than ?-MSH-untreated cells. Our results suggest that COX-2 might be a candidate target for the development of anti-melanogenic agents and ?-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. PMID:22506937

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

2012-06-01

137

Roles of Serotonergic and Adrenergic Receptors in the Antinociception of Selective Cyclooxygenase-2 Inhibitor in the Rat Spinal Cord  

PubMed Central

Background The analgesic mechanisms of cyclooxygenase (COX)-2 inhibitors have been explained mainly on the basis of the inhibition of prostaglandin biosynthesis. However, several lines of evidence suggest that their analgesic effects are mediated through serotonergic or adrenergic transmissions. We investigated the roles of these neurotransmitters in the antinociception of a selective COX-2 inhibitor at the spinal level. Methods DUP-697, a selective COX-2 inhibitor, was delivered through an intrathecal catheter to male Sprague-Dawley rats to examine its effect on the flinching responses evoked by formalin injection into the hindpaw. Subsequently, the effects of intrathecal pretreatment with dihydroergocristine, prazosin, and yohimbine, which are serotonergic, ?1 adrenergic and ?2 adrenergic receptor antagonists, respectively, on the analgesia induced by DUP-697 were assessed. Results Intrathecal DUP-697 reduced the flinching response evoked by formalin injection during phase 1 and 2. But, intrathecal dihydroergocristine, prazosin, and yohimbine had little effect on the antinociception of intrathecal DUP-697 during both phases of the formalin test. Conclusions Intrathecal DUP-697, a selective COX-2 inhibitor, effectively relieved inflammatory pain in rats. Either the serotonergic or adrenergic transmissions might not be involved in the analgesic activity of COX-2 inhibitors at the spinal level.

Jeong, Hye Jin; Lee, Seong Heon; Cho, Soo Young; Lee, Cha Sup; Jeong, Cheol Won; Yoon, Myung Ha

2011-01-01

138

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

PubMed Central

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.

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

2008-01-01

139

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

SciTech Connect

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.

Colleselli, Daniela [Pneumology Service-Division of General Internal Medicine, Department of Internal Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria); Bijuklic, Klaudija [Inflammation Research, Laboratory Division of General Internal Medicine, Department of Internal Medicine, Medical University of Innsbruck (Austria); Mosheimer, Birgit A. [Inflammation Research, Laboratory Division of General Internal Medicine, Department of Internal Medicine, Medical University of Innsbruck (Austria); Kaehler, Christian M. [Pneumology Service-Division of General Internal Medicine, Department of Internal Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck (Austria)]. E-mail: C.M.Kaehler@uibk.ac.at

2006-09-10

140

COX-2 and Prostate Cancer Angiogenesis.  

National Technical Information Service (NTIS)

Cyclooxygenase-2 (COX-2) is an inducible enzyme which catalyzes the conversion of arachidonic acid to prostaglandins and has previously been demonstrated to play a role in carcinogenesis. We demonstrated that COX-2 and one of its major prostaglandin produ...

A. C. Levine

2003-01-01

141

COX-2 and Prostate Cancer Angiogenesis.  

National Technical Information Service (NTIS)

Cyclooxygenase-2 (COx-2%) is an inducible enzyme which catalyzes the conversion of arachidonic acid to prostaglandins and has previously been demonstrated to play a role in carcinogenesis. We demonstrated that COX-2 and one of its major prostaglandin prod...

A. C. Levine

2002-01-01

142

Cox-2 and Prostate Cancer Angiogenesis.  

National Technical Information Service (NTIS)

Cyclooxygenase-2 (COX-2) is an inducible enzyme which catalyzes the conversion of arachidonic acid to prostaglandins and has previously been demonstrated to play a role in carcinogenesis. We demonstrated that COX-2 and one of its major prostaglandin produ...

A. C. Levine

2001-01-01

143

Periganglionic inflammation elicits a distally radiating pain hypersensitivity by promoting COX-2 induction in the dorsal root ganglion  

PubMed Central

We have developed a model in which inflammation contiguous to and within a dorsal root ganglion (DRG) was generated by local application of complete Freund’s adjuvant (CFA) to the L4 lumbar spinal nerve as it exits from the intervertebral foramen. The periganglionic inflammation (PGI) elicited a marked reduction in withdrawal threshold to mechanical stimuli and an increase in heat pain sensitivity in the ipsilateral hindpaw in the absence of any hindpaw inflammation. The pain sensitivity appeared within hours and lasted for a week. The PGI also induced a prominent increase in IL-1 ? and TNF-? levels in the DRG and of cyclooxygenase-2 (COX-2) expression in neurons and satellite cells. A selective COX-2 inhibitor reduced the PGI-induced hyperalgesia. We also show that IL-1 ? induces COX-2 expression and prostaglandin release in DRG neurons in vitro in a MAP kinase-dependent fashion. The COX-2 induction was prevented by ERK and p38 inhibitors. We conclude that periganglionic inflammation increases cytokine levels, including IL-1 ?, leading to the transcription of COX-2 and prostaglandin production in the affected DRG, and thereby to the development of a dermatomally distributed pain hypersensitivity.

Amaya, Fumimasa; Samad, Tarek A.; Barrett, Lee; Broom, Daniel C.; Woolf, Clifford J.

2009-01-01

144

Celecoxib inhibits MDR1 expression through COX2-dependent mechanism in human hepatocellular carcinoma (HepG2) cell line  

Microsoft Academic Search

The role of COX-2 in the regulation of the expression of MDR1, a P-glycoprotein involved in hepatocellular carcinoma cell\\u000a line, HepG2, was studied in the present investigation. Celecoxib, a selective inhibitor of COX-2, at 25 ?M concentration increased\\u000a the accumulation of doxorubicin in HepG2 cells and enhanced the sensitivity of the cells to doxorubicin by tenfold. The induction\\u000a of MDR1 expression

Karnati R. Roy; Gorla V. Reddy; Leela Maitreyi; Smita Agarwal; Chandrani Achari; Shireen Vali; Pallu Reddanna

2010-01-01

145

Induction of COX-2 protein expression by vanadate in A549 human lung carcinoma cell line through EGF receptor and p38 MAPK-mediated pathway  

SciTech Connect

Vanadate is a transition metal widely distributed in the environment. It has been reported that vanadate associated with air pollution particles can modify DNA synthesis, causing cell growth arrest, and apoptosis. Moreover, vanadium exposure was also found to cause the synthesis of inflammatory cytokines, such as interleukin-1, tumor necrosis factor-{alpha}, and prostaglandin E{sub 2}. Here, we found that exposure of A549 human lung carcinoma cells to vanadate led to extracellular signal-regulated kinase, c-Jun NH{sub 2}-terminal protein kinases (JNKs), p38 mitogen-activated protein kinase (p38) activation, and COX-2 protein expression in a dose-dependent manner. SB203580, a p38 MAPK inhibitor, but not PD098059 and SP600125, specific inhibitor of MKK1 and selective inhibitor of JNK, respectively, suppressed COX-2 expression. Furthermore, the epithelial growth factor (EGF) receptor specific inhibitor (PD153035) reduced vanadate-induced COX-2 expression. However, scavenging of vanadate-induced reactive oxygen species by catalase, a specific H{sub 2}O{sub 2} inhibitor, or DPI, an NADPH oxidase inhibitor, resulted in no inhibition on COX-2 expression. Together, we suggested that EGF receptor and p38 MAPK signaling pathway may be involved in vanadate-induced COX-2 protein expression in A549 human lung carcinoma cell line.

Chien, P.-S. [Institute of Biotechnology, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China); Mak, O.-T. [Institute of Biotechnology, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China); Department of Life Sciences, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China); Huang, H.-J. [Institute of Biotechnology, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China) and Department of Life Sciences, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan (China)]. E-mail: haojen@mail.ncku.edu.tw

2006-01-13

146

Origins of prostaglandin E2: involvements of cyclooxygenase (COX)-1 and COX-2 in human and rat systems.  

PubMed

Prostaglandin (PG) E2 is a major cyclooxygenase (COX) product at inflammatory sites where it contributes to local increases in blood flow, edema formation, and pain sensitization. Using rats in vivo and rat and human blood in vitro, we have examined the roles of COX-1 and COX-2 in the production of PGE2. In anesthetized rats treated with bacterial lipopolysaccharide (LPS) to induce the expression of COX-2, the marked increase in PGE2 production that followed bolus intravenous injection of arachidonic acid (3 mg x kg(-1)) was strongly inhibited by diclofenac but largely unaffected by the COX-2-selective inhibitor DFP (5,5- dimethyl-3-(2-propoxy)-4-methanesulfonylphenyl)-2(5H)-furanone). In rat blood in vitro, aspirin strongly inhibited the production of PGE2 that followed either acute exposure to calcium ionophore, A23187 (calcimycin) (50 microM, 15 min), or incubation with LPS for 18 h. In contrast, human whole blood only produced significant levels of PGE2 when incubated with LPS. Rat leukocytes expressed COX-2 and produced PGE2 when exposed to LPS but not when acutely stimulated with A23187. Rat platelets, but not human platelets, also produced significant amounts of PGE2 when acutely stimulated with A23187. These data show that when exposed to an inflammatory stimulus, rat whole blood produces increased levels of PGE2 through induction of COX-2 in blood leukocytes. Rat blood, unlike human blood, may also produce copious amounts of PGE2 via the actions of COX-1 enzyme constitutively present in platelets. These data may well explain why in rats COX-2-selective inhibitors have been reported not to produce the full anti-inflammatory effects associated with standard nonsteroid anti-inflammatory drugs. PMID:12438520

Giuliano, Francesco; Warner, Timothy D

2002-12-01

147

Dual inhibition of 5-LOX and COX-2 suppresses esophageal squamous cell carcinoma.  

PubMed

COX-2 and 5-LOX are up-regulated in ESCC. This study aims to determine the efficacy of COX-2 inhibitor, 5-LOX inhibitor and their combination on ESCC. Nimesulide can suppress cell growth and promote apoptosis, accompanied with a decrease of PGE(2) production. AA861 has the similar effect with a down-regulation of LTB(4). In animal experiment, the tumor volumes in drug-treated groups were significantly smaller with the lowest rates of Ki-67 positive cells. In conclusion, either COX-2 inhibitor or 5-LOX inhibitor can suppress ESCC. Dual inhibition of COX-2 and 5-LOX pathway may present a superior anticancer efficacy to either inhibition of COX-2 or 5-LOX alone. PMID:21652147

Shi, Hai-yun; Lv, Fu-jing; Zhu, Sheng-tao; Wang, Qing-gang; Zhang, Shu-tian

2011-10-01

148

Celecoxib inhibits MDR1 expression through COX-2-dependent mechanism in human hepatocellular carcinoma (HepG2) cell line.  

PubMed

The role of COX-2 in the regulation of the expression of MDR1, a P-glycoprotein involved in hepatocellular carcinoma cell line, HepG2, was studied in the present investigation. Celecoxib, a selective inhibitor of COX-2, at 25 microM concentration increased the accumulation of doxorubicin in HepG2 cells and enhanced the sensitivity of the cells to doxorubicin by tenfold. The induction of MDR1 expression by PGE2 and its downregulation by celecoxib or by COX-2 knockdown suggests that the enhanced sensitivity of HepG2 cells to doxorubicin by celecoxib is mediated by the downregulation of MDR1 expression, through COX-2-dependent mechanism. Further studies revealed the involvement of AP-1 in the celecoxib-induced downregulation of MDR1 expression. These experimental studies correlated well with in silico predictions and further suggested the inactivation of the signal transduction pathways involving ERK, JNK and p38. The present study thus demonstrates the usefulness of COX-2 intervention in overcoming the drug resistance in HepG2 cells. PMID:19685055

Roy, Karnati R; Reddy, Gorla V; Maitreyi, Leela; Agarwal, Smita; Achari, Chandrani; Vali, Shireen; Reddanna, Pallu

2010-04-01

149

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

PubMed

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. PMID:17308870

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

150

COX-2 Protects against Atherosclerosis Independently of Local Vascular Prostacyclin: Identification of COX-2 Associated Pathways Implicate Rgl1 and Lymphocyte Networks  

PubMed Central

Cyxlo-oxygenase (COX)-2 inhibitors, including traditional nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with increased cardiovascular side effects, including myocardial infarction. We and others have shown that COX-1 and not COX-2 drives vascular prostacyclin in the healthy cardiovascular system, re-opening the question of how COX-2 might regulate cardiovascular health. In diseased, atherosclerotic vessels, the relative contribution of COX-2 to prostacyclin formation is not clear. Here we have used apoE?/?/COX-2?/? mice to show that, whilst COX-2 profoundly limits atherosclerosis, this protection is independent of local prostacyclin release. These data further illustrate the need to look for new explanations, targets and pathways to define the COX/NSAID/cardiovascular risk axis. Gene expression profiles in tissues from apoE?/?/COX-2?/? mice showed increased lymphocyte pathways that were validated by showing increased T-lymphocytes in plaques and elevated plasma Th1-type cytokines. In addition, we identified a novel target gene, rgl1, whose expression was strongly reduced by COX-2 deletion across all examined tissues. This study is the first to demonstrate that COX-2 protects vessels against atherosclerotic lesions independently of local vascular prostacyclin and uses systems biology approaches to identify new mechanisms relevant to development of next generation NSAIDs.

Kirkby, Nicholas S.; Lundberg, Martina H.; Wright, William R.; Warner, Timothy D.; Paul-Clark, Mark J.; Mitchell, Jane A.

2014-01-01

151

The Cost-Effectiveness of Acetaminophen, NSAIDs, and Selective COX2 Inhibitors in the Treatment of Symptomatic Knee Osteoarthritis  

Microsoft Academic Search

ObjectiveThe objective of this study was to conduct an economic evaluation of rofecoxib and celecoxib compared with high-dose acetaminophen or ibuprofen with and without misoprostol for patients with symptomatic knee osteoarthritis (OA).

Celia C. Kamath; Hilal Maradit Kremers; David J. Vanness; W. Michael O'Fallon; Rosa L. Cabanela; Sherine E. Gabriel

2003-01-01

152

Evidence for a Pro-Proliferative Feedback Loop in Prostate Cancer: The Role of Epac1 and COX-2-Dependent Pathways  

PubMed Central

Objective In human prostate cancer cells, a selective Epac agonist, 8-CPT-2Me-cAMP, upregulates cell proliferation and survival via activation of Ras-MAPK and PI- 3-kinase-Akt-mTOR signaling cascades. Here we examine the role of inflammatory mediators in Epac1-induced cellular proliferation by determining the expression of the pro-inflammatory markers p-cPLA2, COX-2, and PGE2 in prostate cancer cells treated with 8-CPT-2Me-cAMP. Methods We employed inhibitors of COX-2, mTORC1, and mTORC2 to probe cyclic AMP-dependent pathways in human prostate cancer cells. RNAi targeting Epac1, Raptor, and Rictor was also employed in these studies. Results 8-CPT-2Me-cAMP treatment caused a 2–2.5-fold increase of p-cPLA2S505, COX-2, and PGE2 levels in human prostate cancer cell lines. Pretreatment of cells with the COX-2 inhibitor SC-58125 or the EP4 antagonist AH-23848, or with an inhibitor of mTORC1 and mTORC2, Torin1, significantly reduced the Epac1-dependent increase of p-cPLA2 and COX-2, p-S6-kinaseT389, and p-AKTS473. In addition, Epac1-induced protein and DNA synthesis were greatly reduced upon pretreatment of cells with either COX-2, EP4, or mTOR inhibitors. Transfection of prostate cancer cells with Epac1 dsRNA, Raptor dsRNA, or Rictor dsRNA profoundly reduced Epac1-dependent increases in p-cPLA2 and COX-2. Conclusion We show that Epac1, a downstream effector of cAMP, functions as a pro-inflammatory modulator in prostate cancer cells and promotes cell proliferation and survival by upregulating Ras-MAPK, and PI 3-kinase-Akt-mTOR signaling.

Misra, Uma Kant; Pizzo, Salvatore Vincent

2013-01-01

153

Selective and non-selective cyclooxygenase inhibitors delay stress fracture healing in the rat ulna.  

PubMed

Anti-inflammatory drugs are widely used to manage pain associated with stress fractures (SFxs), but little is known about their effects on healing of those injuries. We hypothesized that selective and non-selective anti-inflammatory treatments would retard the healing of SFx in the rat ulna. SFxs were created by cyclic loading of the ulna in Wistar rats. Ulnae were harvested 2, 4 or 6 weeks following loading. Rats were treated with non-selective NSAID, ibuprofen (30 mg/kg/day); selective COX-2 inhibition, [5,5-dimethyl-3-3 (3 fluorophenyl)-4-(4 methylsulfonal) phenyl-2 (5H)-furanone] (DFU) (2.0 mg/kg/day); or the novel c5a anatagonist PMX53 (10 mg/kg/day, 4 and 6 weeks only); with appropriate vehicle as control. Quantitative histomorphometric measurements of SFx healing were undertaken. Treatment with the selective COX-2 inhibitor, DFU, reduced the area of resorption along the fracture line at 2 weeks, without affecting bone formation at later stages. Treatment with the non-selective, NSAID, ibuprofen decreased both bone resorption and bone formation so that there was significantly reduced length and area of remodeling and lamellar bone formation within the remodeling unit at 6 weeks after fracture. The C5a receptor antagonist PMX53 had no effect on SFx healing at 4 or 6 weeks after loading, suggesting that PMX53 would not delay SFx healing. Both selective COX-2 inhibitors and non-selective NSAIDs have the potential to compromise SFx healing, and should be used with caution when SFx is diagnosed or suspected. PMID:22847634

Kidd, Lisa J; Cowling, Nick R; Wu, Andy C; Kelly, Wendy L; Forwood, Mark R

2013-02-01

154

Pharmacology of a selective cyclooxygenase-2 inhibitor, HN-56249: a novel compound exhibiting a marked preference for the human enzyme in intact cells  

Microsoft Academic Search

HN-56249 (3-(2,4-dichlorothiophenoxy)-4-methylsulfonylamino-benzenesulfonamide), a highly selective cyclooxygenase (COX)-2 inhibitor, is the prototype of a novel series of COX inhibitors comprising bicyclic arylethersulfonamides; of this series HN-56249 is the most potent and selective human COX-2 inhibitor. HN-56249 inhibited platelet aggregation as a measure of COX-1 activity only moderately (IC50 26.5ǃ.7 µM). In LPS-stimulated monocytic cells the release of prostaglandin (PG) F1! as

J. Berg; H. Fellier; T. Christoph; P. Kremminger; M. Hartmann; H. Blaschke; F. Rovensky; R. Towart; D. Stimmeder

2000-01-01

155

Frequent Co-Localization of Cox-2 and Laminin-5 ?2 Chain at the Invasive Front of Early-Stage Lung Adenocarcinomas  

PubMed Central

Laminin-5 is an extracellular matrix protein that plays a key role in cell migration and tumor invasion. Cox-2 is an induced isoform of cyclooxygenases that plays an important role in carcinogenesis, suppression of apoptosis, angiogenesis, and metastasis of colon cancer. We report frequent co-expression of cox-2 and laminin-5 at the invasive front of early-stage lung adenocarcinomas. We investigated the expression of cox-2 and laminin-5 immunohistochemically in 102 cases of small-sized lung adenocarcinoma (maximum dimension, 2 cm or less). Cox-2 and laminin-5 were expressed in 97 (95.1%) and 82 (80.4%) cases, respectively. Both were preferentially localized in cancer cells at the cancer-stroma interface, although cox-2 tended to show a diffuse staining pattern in some cases. A comparison of their staining patterns revealed a striking similarity in their distribution in 24 cases, and a partial overlap between their localization in another 20 cases. Moreover, an overall correlation was found between the expression levels of cox-2 and laminin-5 (P = 0.018). To gain insight into the mechanisms that regulate the expression of these proteins, we additionally studied their expression in 58 cases of stage I lung adenocarcinoma, in which p53 status was determined by immunohistochemistry, polymerase chain reaction-single strand conformation polymorphism analysis, and direct sequencing. The results showed that tumors with mutant p53 tended to express more cox-2 than those with wild-type p53 (P = 0.080). Also, tumors that overexpressed p53 had higher levels of cox-2 and laminin-5 than those without p53 overexpression (P = 0.032 and 0.047, respectively). Further immunohistochemical analysis showed that tumors that overexpressed both epidermal growth factor receptor (EGFR) and erbB-2 had higher levels of cox-2 and laminin-5 than those without concomitant overexpression of these proteins (P = 0.014 and P = 0.018, respectively). To see whether EGFR signaling is involved in cox-2 and laminin-5 expression, we further conducted in vitro analyses using six lung adenocarcinoma cell lines (A549, HLC-1, ABC-1, LC-2/ad, VMRC-LCD, and L27). Western blot analyses showed that cox-2 mRNA levels, and to a lesser extent laminin-5 ?2 mRNA levels, correlated with the expression levels of erbB-2 and the phosphorylated form of MAPK/ERK-1/2 protein. The addition of transforming growth factor-? increased both cox-2 and laminin-5 ?2 mRNA levels in A549, ABC-1, and L27 with different kinetics; the induction of cox-2 occurred earlier than that of laminin-5 ?2. Finally, the migration of ABC-1 cells was inhibited by MAP kinase kinase inhibitor PD98059 and a selective cox-2 inhibitor NS-398. In contrast, the migration of A549 cells was inhibited by PD98059, but much less effectively by NS-398. These results suggest that co-stimulatory mechanisms may exist that increase the expression of cox-2 and laminin-5 at the invasive front of lung adenocarcinomas and that EGFR signaling could be one of the mechanisms. Further investigations are warranted concerning the role of cox-2 and laminin-5 in cancer cell invasion and the significance of p53 and EGFR signaling in the regulation of cox-2 and laminin-5 expression.

Niki, Toshiro; Kohno, Takashi; Iba, Sanae; Moriya, Yasumitsu; Takahashi, Yoko; Saito, Miyuki; Maeshima, Arafumi; Yamada, Tesshi; Matsuno, Yoshihiro; Fukayama, Masashi; Yokota, Jun; Hirohashi, Setsuo

2002-01-01

156

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

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-?B subunit nuclear protein expression. SP-600125 and lactacystin, JNK and NF-?B 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-?B and activator protein-1 proinflammatory pathways and downregulating ROS production and ET-1 transcription, thus contributing to the anti-inflammatory properties of glitazones. PMID:24727493

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

157

Ubiquitin-proteasomal degradation of COX-2 in TGF-? stimulated human endometrial cells is mediated through endoplasmic reticulum mannosidase I.  

PubMed

Cyclooxygenase (COX)-2 is a key regulatory enzyme in the production of prostaglandins (PG) during various physiological processes. Mechanisms of COX-2 regulation in human endometrial stromal cells (human endometrial stromal cells) are not fully understood. In this study, we investigate the role of TGF-? in the regulation of COX-2 in human uterine stromal cells. Each TGF-? isoform decreases COX-2 protein level in human uterine stromal cells in Smad2/3-dependent manner. The decrease in COX-2 is accompanied by a decrease in PG synthesis. Knockdown of Smad4 using specific small interfering RNA prevents the decrease in COX-2 protein, confirming that Smad pathway is implicated in the regulation of COX-2 expression in human endometrial stromal cells. Pretreatment with 26S proteasome inhibitor, MG132, significantly restores COX-2 protein and PG synthesis, indicating that COX-2 undergoes proteasomal degradation in the presence of TGF-?. In addition, each TGF-? isoform up-regulates endoplasmic reticulum (ER)-mannosidase I (ERManI) implying that COX-2 degradation is mediated through ER-associated degradation pathway in these cells. Furthermore, inhibition of ERManI activity using the mannosidase inhibitor (kifunensine), or small interfering RNA-mediated knockdown of ERManI, prevents TGF-?-induced COX-2 degradation. Taken together, these studies suggest that TGF-? promotes COX-2 degradation in a Smad-dependent manner by up-regulating the expression of ERManI and thereby enhancing ER-associated degradation and proteasomal degradation pathways. PMID:22109885

Singh, Mohan; Chaudhry, Parvesh; Parent, Sophie; Asselin, Eric

2012-01-01

158

Antitumor effects of celecoxib in COX-2 expressing and non-expressing canine melanoma cell lines.  

PubMed

Cyclooxygenase-2 (COX-2) is a potential target for chemoprevention and cancer therapy. Celecoxib, a selective COX-2 inhibitor, inhibits cell growth of various types of human cancer including malignant melanoma. In dogs, oral malignant melanoma represents the most common oral tumor and is often a fatal disease. Therefore, there is a desperate need to develop additional therapeutic strategies. The purpose of this study was to investigate the anticancer effects of celecoxib on canine malignant melanoma cell lines that express varying levels of COX-2. Celecoxib induced a significant anti-proliferative effect in both LMeC and CMeC-1 cells. In the CMeC cells, treatment of 50??M celecoxib caused an increase in cells in the G0/G1 and a decreased proportion of cells in G-2 phase. In the LMeC cells, 50??M of celecoxib led to an increase in the percentage of cells in the sub-G1 phase and a significant activation of caspase-3 when compared to CMeC-1 cells. In conclusion, these results demonstrate that celecoxib exhibits antitumor effects on canine melanoma LMeC and CMeC-1 cells by induction of G1-S cell cycle arrest and apoptosis. Our data suggest that celecoxib might be effective as a chemotherapeutic agent against canine malignant melanoma. PMID:24656746

Seo, Kyoung-Won; Coh, Ye-Rin; Rebhun, Robert B; Ahn, Jin-Ok; Han, Sei-Myung; Lee, Hee-Woo; Youn, Hwa-Young

2014-06-01

159

Effects of a COX2 Preferential Agent Nimesulide on TNBS-Induced Acute Inflammation in the Gut  

Microsoft Academic Search

In inflammatory bowel disease, increased production of prostaglandins by cyclooxy- genase-2 (COX-2) contributes to bowel dysfunction, inflammatory edema, and hyperemia suggesting that inhibitors of COX-2 may have beneficial effect in gut inflammation. We compared the effects of nimesulide, a preferential COX-2 inhibitor, with those of indomethacin, acetylsalicylic acid (ASA), and dexamethasone in a 24-h model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis

Esko Kankuri; Kirsi Vaali; Riitta Korpela; Ilari Paakkari; Heikki Vapaatalo; Eeva Moilanen

2001-01-01

160

Cox-2 inhibition enhances the activity of sunitinib in human renal cell carcinoma xenografts  

PubMed Central

Background: Sunitinib (Su), a tyrosine kinase inhibitor of VEGFR, is effective at producing tumour response in clear cell renal cell carcinoma (cRCC), but resistance to therapy is inevitable. As COX-2 is a known mediator of tumour growth, we explored the potential benefit of COX-2 inhibition in combination with VEGFR inhibition in attempts at delaying tumour progression on Su. Methods: COX-2 expression was compared with areas of hypoxia in tumours that progressed on Su vs untreated tumours. Mice bearing human cRCC xenografts were treated with Su and the COX-2 inhibitor, celecoxib, and the effects on tumour growth were assessed. Sequential vs concurrent regimens were compared. Results: COX-2 expression was increased in cRCC xenografts in areas of tumour hypoxia. The combination of Su and celecoxib achieved longer times to tumour progression compared to treatment with either agent alone or to untreated control animals in four models. This effect was seen with concurrent but not with sequential therapy. Conclusion: COX-2 inhibition can extend the effectiveness of VEGFR inhibition. This effect is dependent on the timing of therapy. Clinical trials combining Su and COX-2 inhibitors should be considered as a means delaying time to progression on sunitinib in patients with metastatic cRCC.

Wang, X; Zhang, L; O'Neill, A; Bahamon, B; Alsop, D C; Mier, J W; Goldberg, S N; Signoretti, S; Atkins, M B; Wood, C G; Bhatt, R S

2013-01-01

161

Combined Effects of Cyclooxygenase-1 and Cyclooxygenase-2 Selective Inhibitors on Ovarian Carcinoma in Vivo  

PubMed Central

The present study was designed to investigate the combined effects of cyclooxygenase (COX)-1 and COX-2 selective inhibitors on human ovarian SKOV-3 carcinoma cells xenograft-bearing mice. The animals were treated with 3 mg/kg SC-560 (a COX-1 selective inhibitor) alone, 25 mg/kg celecoxib (a COX-2 selective inhibitor) alone, or SC-560/celecoxib by gavage, twice a day for three weeks. To test the mechanism of inhibition of tumor growth by COX selective inhibitors, the index of proliferating cells in tumor tissues was determined by immunostaining and the index of apoptotic cells by the terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. The inhibitory rate on tumor growth in the combination group was 35.54% which is significant statistically compared with that of the control group (P < 0.05). In the combination group, the index of cell proliferation and apoptosis were 12.40% and 51.03% respectively, which are significant statistically compared with those of the control group (22.56%, 19.07%, all P < 0.05). These studies indicate that synergism between two COX inhibitors and inhibitor combination treatment has particular potential for chemoprevention of ovarian cancer growth.

Li, Wei; Wang, Jie; Jiang, Hong-Ru; Xu, Xiao-Li; Zhang, Jun; Liu, Mei-Lin; Zhai, Ling-Yun

2011-01-01

162

COX-2 overexpression increases malignant potential of human glioma cells through Id1.  

PubMed

Increased COX-2 expression directly correlates with glioma grade and is associated with shorter survival in glioblastoma (GBM) patients. COX-2 is also regulated by epidermal growth factor receptor signaling which is important in the pathogenesis of GBMs. However, COX-2 expression has not been previously shown to directly alter malignancy of GBMs. Id1 is a member of the helix-loop-helix (HLH) family of transcriptional repressors that act as dominant-negative inhibitors of basic-HLH factors. This factor has been shown to be regulated by COX-2 in breast carcinoma cells and recent studies suggest that Id1 may also be involved in the genesis/progression of gliomas. We now show that COX-2 increases the aggressiveness of GBM cells. GBM cells with COX-2 overexpression show increased growth of colonies in soft agar. Tumorigenesis in vivo is also increased in both subcutaneous flank and orthotopic intracranial tumor models. COX-2 overexpression induces Id1 expression in two GBM cell lines suggesting a role for Id1 in glioma transformation/tumorigenesis. Furthermore, we find direct evidence of a role for Id1 with significant suppression of in vitro transformation and in vivo tumorigenesis in COX-2-overexpressing GBM cells where Id1 has been knocked down. In fact, Id1 is even more efficient at enhancing transformation/tumorigenesis of GBM cells than COX-2. Finally, GBM cells with COX-2 or Id1 overexpression show greater migration/invasive potential and tumors that arise from these cells also display increased microvessel density, results in line with the increased malignant potential seen in these cells. Thus, COX-2 enhances the malignancy of GBM cells through induction of Id1. PMID:24659686

Xu, Kaiming; Wang, Lanfang; Shu, Hui-Kuo G

2014-03-15

163

COX-2 overexpression increases malignant potential of human glioma cells through Id1  

PubMed Central

Increased COX-2 expression directly correlates with glioma grade and is associated with shorter survival in glioblastoma (GBM) patients. COX-2 is also regulated by epidermal growth factor receptor signaling which is important in the pathogenesis of GBMs. However, COX-2 expression has not been previously shown to directly alter malignancy of GBMs. Id1 is a member of the helix-loop-helix (HLH) family of transcriptional repressors that act as dominant-negative inhibitors of basic-HLH factors. This factor has been shown to be regulated by COX-2 in breast carcinoma cells and recent studies suggest that Id1 may also be involved in the genesis/progression of gliomas. We now show that COX-2 increases the aggressiveness of GBM cells. GBM cells with COX-2 overexpression show increased growth of colonies in soft agar. Tumorigenesis in vivo is also increased in both subcutaneous flank and orthotopic intracranial tumor models. COX-2 overexpression induces Id1 expression in two GBM cell lines suggesting a role for Id1 in glioma transformation/tumorigenesis. Furthermore, we find direct evidence of a role for Id1 with significant suppression of in vitro transformation and in vivo tumorigenesis in COX-2-overexpressing GBM cells where Id1 has been knocked down. In fact, Id1 is even more efficient at enhancing transformation/tumorigenesis of GBM cells than COX-2. Finally, GBM cells with COX-2 or Id1 overexpression show greater migration/invasive potential and tumors that arise from these cells also display increased microvessel density, results in line with the increased malignant potential seen in these cells. Thus, COX-2 enhances the malignancy of GBM cells through induction of Id1.

Xu, Kaiming; Wang, Lanfang; Shu, Hui-Kuo G.

2014-01-01

164

ROLE OF COX-2 IN THE BIOACTIVATION OF METHYLENEDIANILINE AND IN ITS PROLIFERATIVE EFFECTS IN VASCULAR SMOOTH MUSCLE CELLS  

PubMed Central

4,4?-Methylenedianiline (DAPM) is an aromatic diamine used directly in the production of polyurethane forms and epoxy resins, or as a precursor to MDI in the manufacture of some polyurethanes. In our prior experiments, we showed that chronic, intermittent treatment of female rats with DAPM resulted in vascular medial hyperplasia of pulmonary arteries. In addition, treatment of vascular smooth muscle cells (VSMC) in culture with DAPM increased rates of proliferation in a manner that was inhibited by cotreatment with N-acetylcysteine but was not associated with oxidative stress. We thus hypothesized that NAC treatment inhibited DAPM toxicity by competing for binding reactive intermediates formed through DAPM metabolism. Because the peroxidase enzyme cyclooxygenase is constitutively expressed in VSMC, and because cyclooxygenase is known to metabolize similar aromatic amines to electrophilic intermediates, we further hypothesized that DAPM-induced VSMC proliferation was dependent upon COX-1/2-mediated bioactivation. To test this hypothesis, we treated VSMC with DAPM and measured cell proliferation, COX-2 expression, COX-1/2 activity and levels of covalent binding. DAPM treatment resulted in a dose-dependent increase in proliferation that was abolished by co-treatment with the COX-2-selective inhibitor celecoxib. In addition, DAPM exposure increased rates of proliferation in VSMC isolated from wildtype but not COX-2 (?/?) mice. Paradoxically, treatment with DAPM reduced cellular production of PGE2 and PGF2?, but dose-dependently increased COX-2 protein levels. Covalent binding of [14C]-DAPM to VSMC biomolecules was greater in wildtype than in COX-2 (?/?) cells. However, covalent binding of [14C]-DAPM was not altered by cotreatment with a nonselective inhibitor of cytochromes P450. These studies thus suggest that DAPM-induced VSMC proliferation may be due to bioactivation of DAPM, perhaps through the action of cyclooxygenase. The data furthermore suggest that DAPM’s mechanism of action may possibly involve inhibition or suicide inactivation of COX-2. In addition, because we observed an increase in DAPM-induced VSMC proliferation in cells isolated from female compared to male rats, further studies into the potential interplay between DAPM, the estrogen receptor, and COX-2 seem warranted.

Hebert, Valeria Y.; Jones, Brandon Chad; Mifflin, Randy C.; Dugas, Tammy R.

2011-01-01

165

Role of COX-2 in the bioactivation of methylenedianiline and in its proliferative effects in vascular smooth muscle cells.  

PubMed

4,4'-Methylenedianiline (DAPM) is an aromatic diamine used directly in the production of polyurethane foams and epoxy resins, or as a precursor to MDI in the manufacture of some polyurethanes. In our prior experiments, we showed that chronic, intermittent treatment of female rats with DAPM resulted in vascular medial hyperplasia of pulmonary arteries. In addition, treatment of vascular smooth muscle cells (VSMC) in culture with DAPM increased the rates of proliferation in a manner that was inhibited by co-treatment with N-acetylcysteine but was not associated with oxidative stress. We thus hypothesized that NAC treatment inhibited DAPM toxicity by competing for binding reactive intermediates formed through DAPM metabolism. Because the peroxidase enzyme cyclooxygenase is constitutively expressed in VSMC, and because cyclooxygenase is known to metabolize similar aromatic amines to electrophilic intermediates, we further hypothesized that DAPM-induced VSMC proliferation was dependent upon COX-1/2-mediated bioactivation. To test this hypothesis, we treated VSMC with DAPM and measured cell proliferation, COX-2 expression, COX-1/2 activity, and levels of covalent binding. DAPM treatment resulted in a dose-dependent increase in proliferation that was abolished by co-treatment with the COX-2-selective inhibitor celecoxib. In addition, DAPM exposure increased the rates of proliferation in VSMC isolated from wild-type but not COX-2 (-/-) mice. Paradoxically, treatment with DAPM reduced the cellular production of PGE(2) and PGF(2?), but dose-dependently increased the COX-2 protein levels. Covalent binding of [(14)C]-DAPM to VSMC biomolecules was greater in wild-type than in COX-2 (-/-) cells. However, covalent binding of [(14)C]-DAPM was not altered by co-treatment with a nonselective inhibitor of cytochromes P450. These studies thus suggest that DAPM-induced VSMC proliferation may be due to bioactivation of DAPM, perhaps through the action of cyclooxygenase. The data furthermore suggest that DAPM's mechanism of action may possibly involve inhibition or suicide inactivation of COX-2. In addition, because we observed an increase in DAPM-induced VSMC proliferation in cells isolated from female compared to male rats, further studies into the potential interplay between DAPM, the estrogen receptor, and COX-2 seem warranted. PMID:21720929

Hebert, Valeria Y; Jones, Brandon Chad; Mifflin, Randy C; Dugas, Tammy R

2011-12-01

166

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 Central

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, 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.

Candelario-Jalil, Eduardo; Gonzalez-Falcon, Armando; Garcia-Cabrera, Michel; Alvarez, Dalia; Al-Dalain, Said; Martinez, Gregorio; Sonia Leon, Olga; Springer, Joe E.

2006-01-01

167

COX-2 Inhibition by Use of Rofecoxib or High Dose Aspirin Enhances ADP-Induced Platelet Aggregation in Fresh Blood  

PubMed Central

Aim: Increased cardiovascular risk after use of selective or nonselective cyclooxygenase-2 (COX-2)-inhibitors might partly be caused by enhanced platelet aggregability. However, an effect of COX-2 inhibition on platelets has so far not been observed in humans. Methods: We tested in healthy volunteers the effect of COX-2-inhibition nearly in-vivo, i.e. immediately after and even during blood sampling. Results: Measurement within 2 minutes after venipuncture, but not 60 minutes later, showed that 50 mg of rofecoxib (n=12) or 500 (n=8) or 1000 (n=8) mg of aspirin increased ADP-induced platelet aggregation in a whole-blood aggregometer to, respectively, 152, 176 and 204 % of basal level (p<0.01). No significant differences in aggregability were observed after ingestion of 80 mg of aspirin (n=16), or placebo (n=8). Plasma 6-keto-PGF1? was decreased to 74 % after rofecoxib and to 76 and 70 % after 500 and 1000 mg of aspirin but did not change after low dose aspirin. Continuous photometrical measurement of aggregation in blood flowing from a cannulated vein revealed that high dose aspirin did not elicit aggregation by itself, but increased ADP-induced aggregation in proportion to the decrease in prostacyclin formation (r=0.68, p = 0.004). Since in these experiments thromboxane production was virtually absent, the enhanced aggregation after partial COX-2 inhibition was not caused by unopposed thromboxane formation. Conclusions: We conclude that both selective and nonselective COX-2 inhibition enhances ADP-induced platelet aggregation in humans. This effect can only be detected during or immediately after venipuncture, possibly because of the short half-life of prostacyclin.

Borgdorff, Piet; Handoko, M. Louis; Wong, Yeun Ying; Tangelder, Geert Jan

2010-01-01

168

COX-2 expression in stromal fibroblasts self-limits their numbers in lymph node inflammatory responses.  

PubMed

We previously reported the expression of cyclooxygenase (COX)-2 in draining lymph nodes during carrageenin-induced pleurisy of rats. Here, we analyzed histological and immunohistochemical characteristics of COX-2-expressing cells. After carrageenin administration into the pleural cavity of rats, parathymic lymph nodes were enlarged beginning at 8h and peaking from 24 to 48h. Lymphatic follicles disappeared 16h after injection, and numerous macrophages and fibroblasts were observed in the cortical region. COX-2-expressing cells in the cortical region showed characteristic dendritic processes from 16 to 48h and primarily co-localized with stromal fibroblastic reticular cell markers, ?-smooth muscle actin (?-SMA), and desmin. Expression of ?-SMA increased following COX-2 expression. Nimesulide, a COX-2 inhibitor, increased the dendritic processes of COX-2-expressing cells as well as expression of both COX-2 and ?-SMA. These results suggest that COX-2-expressing cells may be stromal fibroblastic cells, which negatively self-regulate their proliferation and modulate tissue remodeling of draining lymph nodes at inflammatory sites. PMID:23587942

Kawamura, Michiko; Tada, Yosihito; Kadoya, Yuichi; Obata, Shuichi; Harada, Yoshiteru

2013-10-01

169

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

PubMed

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. PMID:23008503

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

2013-01-01

170

The clinical pharmacology of cyclooxygenase-2-selective and dual inhibitors.  

PubMed

Over the past decade, there have been several nonsteroidal anti-inflammatory drugs (NSAIDS) introduced in veterinary medicine with an increased gastrointestinal safety profile consistent with a cyclooxygenase (COX)-1-sparing effect. More recently, an NSAID with additional 5-lipoxygenase (5-LOX) activity has also been approved for use. Although it is tempting to equate in vitro COX-2/COX-1 and 5-LOX inhibition to overall in vivo safety, the data do not support this approach. The true overall safety for any individual compound is based on its evaluation in laboratory margin-of-safety studies, reproductive safety studies, and blind multicenter field studies in client-owned animals. Therefore, when choosing a COX-2-selective or dual-inhibitor NSAID for clinical use, all in vivo data must be taken into account to understand comparative safety, and continued use must be based on the drug's performance in the individual being treated. Until head-to-head trials in multicenter blind studies are published, comments on comparative safety and effectiveness must be reserved. PMID:16984827

Clark, Terrence P

2006-09-01

171

Influence of COX2 Inhibition by Rofecoxib on Serum and Tumor Progastrin and Gastrin Levels and Expression of PPAR? and Apoptosis-Related Proteins in Gastric Cancer Patients  

Microsoft Academic Search

Cyclooxygenase-2 (COX-2) expression and certain growth hormones, such as gastrin, have been related to gastric carcinogenesis, but little is known about the factors that enhance this COX-2 expression and whether specific blockade of this enzyme has any influence on tumor growth and progression. Our objective was to determine the influence of a specific COX-2 inhibitor, rofecoxib (Vioxx), on serum and

Peter C. Konturek; Stanislaw J. Konturek; Wladyslaw Bielanski; J. Kania; Monika ?uchowicz; Artur Hartwich; Jens F. Rehfeld; Eckhart G. Hahn

2003-01-01

172

The effects of selective and nonselective cyclooxygenase inhibitors on endothelin-1-induced fever in rats.  

PubMed

It was previously shown that sustained fever can be induced in rats by central injection of endothelin-1 (ET-1). This peptide appears to participate in the mechanism(s) of LPS-induced fever, which is reduced by pretreatments with ET(B) receptor antagonists. In this study, we compared the effects of a nonselective cyclooxygenase (COX) inhibitor, indomethacin, with those of two selective COX-2 inhibitors, celecoxib and lumiracoxib, on ET-1-induced fever in rats. Fever induced in conscious animals by ET-1 (1 pmol icv) or LPS (5 mug/kg iv) was prevented by pretreatments with celecoxib (5 and 10 mg/kg) or lumiracoxib (5 mg/kg) given by oral gavage 1 h before stimuli. Lower doses of celecoxib had partial (2.5 mg/kg) or no effect (1 mg/kg). Indomethacin (2 mg/kg ip) partially inhibited fever induced by LPS but had no effect on ET-1-induced fever. The levels of PGE(2) and PGF(2alpha) in the cerebrospinal fluid (CSF) of pentobarbital sodium-anesthetized rats were significantly increased 3 h after the injection of LPS or ET-1. The latter increase was abolished by celecoxib at all tested doses and by indomethacin. In conclusion, selective COX-2 inhibitors were able to prevent ET-1-induced fever, indicating a role for COX-2 in this phenomenon. However, the fact that reduced CSF PG levels obtained with indomethacin and a low dose of celecoxib are not accompanied by changes in fever induced by ET-1, along with the lack of inhibitory effects of indomethacin on ET-1 fever, suggests that the latter might also involve COX-2-independent mechanisms. PMID:15539607

Fabricio, Aline S C; Veiga, Fabiane H; Cristofoletti, Rodrigo; Navarra, Pierluigi; Souza, Gloria E P

2005-03-01

173

Radiation-induced non-targeted response in vivo: role of the TGF?-TGFBR1-COX-2 signalling pathway  

PubMed Central

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-?) and TGF-? 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-? and its receptors was elevated in non-targeted lung tissues after partial body irradiation. In contrast to the predominant expression of TGF-? in stromal and alveolar cells, but not in bronchial epithelial cells, TGF-? 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-? induced signalling pathways were activated in the non-targeted lung tissues. Conclusion: The TGF?-TGFBR1-COX-2 Signalling Pathway has a critical role in radiation-induced non-targeted response in vivo.

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

2013-01-01

174

Over-expression of COX-2 mRNA in colorectal cancer  

PubMed Central

Background Cyclooxygenase-2 (COX-2, PTGS2) is an enzyme involved in the synthesis of prostaglandins and thromboxanes, which are regulators of biologic processes such as inflammation, cell proliferation and angiogenesis. COX-2 over-expression was reported in many (pre) malignant tissues, but data strongly vary and seem to depend on the methodology used. Methods Normal colorectal mucosa and paired cancerous tissue from 60 patients with colorectal cancer was investigated for the levels of COX-2 mRNA by real-time quantitative Polymerase Chain Reaction (qPCR). COX-2 levels were expressed relative to either: tissue weight or levels of the housekeeping genes beta-2 microglobulin (B2M) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Results COX-2 mRNA levels, normalized with respect to tissue weight or mRNA levels of the housekeeping genes B2M or GAPDH, were over-expressed in 80%, 70% and 40% of the colorectal tumor tissues, as compared to the paired adjacent normal colorectal mucosa samples, respectively. Highest mRNA COX-2 ratios tumor/normal were measured when expressed per mg tissue (mean ratio 21.6). When normalized with respect to the housekeeping genes B2M or GAPDH, mean tumor/normal ratios were 16.1 and 7.5, respectively. Conclusion Expression of COX-2 mRNA levels per mg tissue is most simple in comparison to normalization with respect to the housekeeping genes B2M or GAPDH. Levels of COX-2 mRNA are found over-expressed in almost 80% of the colorectal tumors, compared to paired adjacent normal colorectal mucosa, suggesting a role of COX-2 as a potential biomarker for cancer risk, whereas inhibitors of COX-2 could be of value in chemoprevention of colon cancer.

2014-01-01

175

NF?B activates in vivo the synthesis of inducible Cox2 in the brain  

Microsoft Academic Search

Interleukin-1? (IL-1?) induces cyclooxygenase-2 (Cox-2) expression in many of its cellular targets resulting in production and release of prostaglandins. Although IL-1?-induced Cox-2 expression most likely requires activation of nuclear transcription factor kappa B (NF?B) pathway, this has never been formally demonstrated in vivo. We tested this using a specific inhibitor of NF?B activation, the NEMO binding domain (NBD) peptide, that

Agnès Nadjar; Viviane Tridon; Michael J May; Sankar Ghosh; Robert Dantzer; Thierry Amédée; Patricia Parnet

2005-01-01

176

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

SciTech Connect

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.

Dittmann, Klaus H. [Division of Radiobiology and Molecular Environmental Research, Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany)], E-mail: klaus.dittmann@uni-tuebingen.de; Mayer, Claus; Ohneseit, Petra A. [Division of Radiobiology and Molecular Environmental Research, Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Raju, Uma [Department of Experimental Radiation Oncology, University of Texas, M.D. Anderson Cancer Center, Houston, TX (United States); Andratschke, Nickolaus H. [Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie, Klinikum Rechts Der Isar, Technische Universitaet Muenchen, Munich (Germany); Milas, Luka [Department of Experimental Radiation Oncology, University of Texas, M.D. Anderson Cancer Center, Houston, TX (United States); Rodemann, H. Peter [Division of Radiobiology and Molecular Environmental Research, Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany)

2008-01-01

177

Lasiodin Inhibits Proliferation of Human Nasopharyngeal Carcinoma Cells by Simultaneous Modulation of the Apaf-1/Caspase, AKT/MAPK and COX-2/NF-?B Signaling Pathways  

PubMed Central

Rabdosia serra has been widely used for the treatment of the various human diseases. However, the antiproliferative effects and underlying mechanisms of the compounds in this herb remain largely unknown. In this study, an antiproliferative compound against human nasopharyngeal carcinoma (NPC) cells from Rabdosia serra was purified and identified as lasiodin (a diterpenoid). The treatment with lasiodin inhibited cell viability and migration. Lasiodin also mediated the cell morphology change and induced apoptosis in NPC cells. The treatment with lasiodin induced the Apaf-1 expression, triggered the cytochrome-C release, and stimulated the PARP, caspase-3 and caspase-9 cleavages, thereby activating the apoptotic pathways. The treatment with lasiodin also significantly inhibited the phosphorylations of the AKT, ERK1/2, p38 and JNK proteins. The pretreatment with the AKT or MAPK-selective inhibitors considerably blocked the lasiodin-mediated inhibition of cell proliferation. Moreover, the treatment with lasiodin inhibited the COX-2 expression, abrogated NF-?B binding to the COX-2 promoter, and promoted the NF-?B translocation from cell nuclei to cytosol. The pretreatment with a COX-2-selective inhibitor abrogated the lasiodin-induced inhibition of cell proliferation. These results indicated that lasiodin simultaneously activated the Apaf-1/caspase-dependent apoptotic pathways and suppressed the AKT/MAPK and COX-2/NF-?B signaling pathways. This study also suggested that lasiodin could be a promising natural compound for the prevention and treatment of NPC.

Lin, Lianzhu; Deng, Wuguo; Tian, Yun; Chen, Wangbing; Wang, Jingshu; Fu, Lingyi; Shi, Dingbo; Zhao, Mouming; Luo, Wei

2014-01-01

178

Cyclooxygenase2 inhibitor blocks expression of mediators of renal injury in a model of diabetes and hypertension1  

Microsoft Academic Search

Cyclooxygenase-2 inhibitor blocks expression of mediators of renal injury in a model of diabetes and hypertension.BackgroundWe previously reported that renal cortical cyclooxygenase (COX-2) expression increased following subtotal nephrectomy, and chronic treatment with a selective COX-2 inhibitor, SC58236, reduced proteinuria and retarded the development of glomerulosclerosis. The present studies were designed to examine the effects of COX-2 inhibition in a model

Hui-Fang Cheng; Connie J. Wang; Gilbert W. Moeckel; Ming-Zhi Zhang; James A. Mckanna; Raymond C. Harris

2002-01-01

179

STAT3 and COX2 activation in the guinea-pig brain during fever induced by the Toll-like receptor-3 agonist polyinosinic:polycytidylic acid  

Microsoft Academic Search

Intra-arterial injections of synthetic double-stranded RNA (polyinosinic:polycytidylic acid, PIPC) at a dose of 500 ?g\\/kg\\u000a evoked pronounced fever in guinea-pigs. PIPC-induced fever could be antagonized by treatment with the non-selective cyclooxygenase\\u000a (COX) inhibitor diclofenac and was, in part, attenuated by the administration of the selective COX-2-inhibitor nimesulide\\u000a (dose: 5 mg\\/kg for both COX inhibitors). We further investigated whether direct activation of brain

Thilo Voss; Stephan W. Barth; Christoph Rummel; Rüdiger Gerstberger; Thomas Hübschle; Joachim Roth

2007-01-01

180

Selective cyclooxygenase-2 inhibitor suppresses renal thromboxane production but not proliferative lesions in the MRL/lpr murine model of lupus nephritis  

PubMed Central

Background Proliferative lupus nephritis (LN) is marked by increased renal thromboxane (TXA2) production. Targeting the TXA2 receptor or TXA2 synthase effectively improves renal function in humans with LN and improves glomerular pathology in murine LN. This study was designed to address the following hypotheses: 1) TXA2 production in the MRL/MpJ-Tnfrsf6lpr/J (MRL/lpr) model of proliferative lupus nephritis is COX2-dependent, and 2) COX2 inhibitor therapy improves glomerular filtration rate (GFR), proteinuria, markers of innate immune response, and glomerular pathology. Methods 20 female MRL/lpr and 20 BALB/cJ mice were divided into two equal treatment groups: 1) SC-236, a moderately selective COX2 inhibitor, or 2) vehicle. After treatment from 10 to 20 weeks of age, the effectiveness of inhibition of TXA2 was determined by measuring urine TXB2. Response endpoints measured at 20 weeks of age were renal function (GFR), proteinuria, urine nitrate + nitrite (NOX), and glomerular histopathology. Results SC236 therapy reduced surrogate markers of renal TXA2 production during early, active glomerulonephritis. When this pharmacodynamic endpoint was reached, therapy improved GFR. Parallel reductions in markers of the innate immune response (urine NOX) during therapy were observed. However, the beneficial effect of SC236 therapy on GFR was only transient, and renal histopathology was not improved in late disease. Conclusions These data demonstrate that renal TXA2 production is COX2-dependent in murine LN and suggest that NO production is directly or indirectly COX2-dependent. However, COX2 inhibitor therapy in this model failed to improve renal pathology, making COX2 inhibition a less attractive approach for treating LN.

Oates, Jim C.; Halushka, Perry V.; Hutchison, Florence N.; Ruiz, Philip; Gilkeson, Gary S.

2010-01-01

181

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

PubMed

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 factors such as IGF-I increase cox-2 expression by several complementary mechanisms; hence, decreased cox-2 activity may play a role in the remarkably low mortality from "Western" cancers enjoyed by Third World cultures in which systemic growth factor activity was minimized by quasi-vegan diets complemented by leanness and excellent muscle insulin sensitivity. Practical strategies for achieving a modest degree of calorie restriction may also have potential for down-regulating cox-2 expression while decreasing cancer risk. Soy isoflavones, linked to reduced cancer risk in Asian epidemiology, may suppress cox-2 induction by activating ERbeta. In aggregate, these considerations suggest that a comprehensive lifestyle strategy targeting cox-2 expression and bioactivity may have tremendous potential for cancer prevention. PMID:22001128

McCarty, Mark F

2012-01-01

182

Intracellular gene transfer in action: Dual transcription and multiple silencings of nuclear and mitochondrial cox2 genes in legumes  

PubMed Central

The respiratory gene cox2, normally present in the mitochondrion, was previously shown to have been functionally transferred to the nucleus during flowering plant evolution, possibly during the diversification of legumes. To search for novel intermediate stages in the process of intracellular gene transfer and to assess the evolutionary timing and frequency of cox2 transfer, activation, and inactivation, we examined nuclear and mitochondrial (mt) cox2 presence and expression in over 25 legume genera and mt cox2 presence in 392 genera. Transfer and activation of cox2 appear to have occurred during recent legume evolution, more recently than previously inferred. Many intermediate stages of the gene transfer process are represented by cox2 genes in the studied legumes. Nine legumes contain intact copies of both nuclear and mt cox2, although transcripts could not be detected for some of these genes. Both cox2 genes are transcribed in seven legumes that are phylogenetically interspersed with species displaying only nuclear or mt cox2 expression. Inactivation of cox2 in each genome has taken place multiple times and in a variety of ways, including loss of detectable transcripts or transcript editing and partial to complete gene loss. Phylogenetic evidence shows about the same number (3–5) of separate inactivations of nuclear and mt cox2, suggesting that there is no selective advantage for a mt vs. nuclear location of cox2 in plants. The current distribution of cox2 presence and expression between the nucleus and mitochondrion in the studied legumes is probably the result of chance mutations silencing either cox2 gene.

Adams, Keith L.; Song, Keming; Roessler, Philip G.; Nugent, Jacqueline M.; Doyle, Jane L.; Doyle, Jeff J.; Palmer, Jeffrey D.

1999-01-01

183

Suppressive effects of nimesulide, a selective inhibitor of cyclooxygenase-2, on azoxymethane-induced colon carcinogenesis in mice  

Microsoft Academic Search

The effects of nimesulide, a selective inhibitor of cyclo- oxygenase-2 (COX-2) on azoxymethane (AOM)-induced colon carcinogenesis were investigated in mice. AOM at a dose of 10 mg\\/kg body wt was administered to male ICR mice once a week for 6 weeks. The animals were fed on AIN-76A powder diet containing nimesulide at doses of 200 or 400 p.p.m., starting the

Masato Fukutake; Seiichi Nakatsugi; Takashi Isoi; Mami Takahashi; Toshihisa Ohta; Souichi Mamiya; Yasuaki Taniguchi; Hidetaka Sato; Kazunori Fukuda; Takashi Sugimura; Keiji Wakabayashi

184

The novel benzopyran class of selective cyclooxygenase-2 inhibitors. Part 2: The second clinical candidate having a shorter and favorable human half-life  

SciTech Connect

In this Letter, we provide the structure-activity relationships, optimization of design, testing criteria, and human half-life data for a series of selective COX-2 inhibitors. During the course of our structure-based drug design efforts, we discovered two distinct binding modes within the COX-2 active site for differently substituted members of this class. The challenge of a undesirably long human half-life for the first clinical candidate 1t{sub 1/2} = 360 h was addressed by multiple strategies, leading to the discovery of 29b-(S) (SC-75416) with t{sub 1/2} = 34 h.

Wang, Jane L.; Limburg, David; Graneto, Matthew J.; Springer, John; Hamper, Joseph Rogier Bruce; Liao, Subo; Pawlitz, Jennifer L.; Kurumbail, Ravi G.; Maziasz, Timothy; Talley, John J.; Kiefer, James R.; Carter, Jeffery (Pfizer)

2012-05-29

185

Attenuation of Proinflammatory Responses by S-[6]-Gingerol via Inhibition of ROS/NF-Kappa B/COX2 Activation in HuH7 Cells  

PubMed Central

Introduction. Hepatic inflammation underlies the pathogenesis of chronic diseases such as insulin resistance and type 2 diabetes mellitus. S-[6]-Gingerol has been shown to have anti-inflammatory properties. Important inflammatory mediators of interleukins include nuclear factor ?B (NF?B) and cyclooxygenase 2 (COX2). We now explore the mechanism of anti-inflammatory effects of S-[6]-gingerol in liver cells. Methods. HuH7 cells were stimulated with IL1? to establish an in vitro hepatic inflammatory model. Results. S-[6]-Gingerol attenuated IL1?-induced inflammation and oxidative stress in HuH7 cells, as evidenced by decreasing mRNA levels of inflammatory factor IL6, IL8, and SAA1, suppression of ROS generation, and increasing mRNA levels of DHCR24. In addition, S-[6]-gingerol reduced IL1?-induced COX2 upregulation as well as NF?B activity. Similar to the protective effects of S-[6]-gingerol, both NS-398 (a selective COX2 inhibitor) and PDTC (a selective NF?B inhibitor) suppressed mRNA levels of IL6, IL8, and SAA1. Importantly, PDTC attenuated IL1?-induced overexpression of COX2. Of particular note, the protective effect of S-[6]-gingerol against the IL1?-induced inflammatory response was similar to that of BHT, an ROS scavenger. Conclusions. The findings of this study demonstrate that S-[6]-gingerol protects HuH7 cells against IL1?-induced inflammatory insults through inhibition of the ROS/NF?B/COX2 pathway.

McGrath, Kristine C. Y.; Tran, Van H.; Li, Yi-Ming; Duke, Colin C.; Roufogalis, Basil D.; Heather, Alison K.

2013-01-01

186

Interaction of Apoptotic Cells with Macrophages Upregulates COX-2/PGE2 and HGF Expression via a Positive Feedback Loop  

PubMed Central

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.

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

2014-01-01

187

Evaluation of Cyclooxygenase2 Inhibitor for Potential Chemopreventive Properties in Colon Carcinogenesis  

Microsoft Academic Search

Epidemlologicaland laboratorystudies indicatean inverserelationship between the risk of colon cancer development and intake of nonsteroldal antiinflammatory agents, including aspirin. One of the mechanisms by which nonsteroidal antiinflammatory agents Inhibit colon carcInogenesis Is through the inhibition of prostaglandIn production by cyclooxygenase isozymes (COX-1 and COX-2). Overexpression of COX-2 has been oh served In colon tumors. Thus, selective inhibitors of COX-2 could

Bandaru S. Reddy; Chinthalapally V. Rao; Karen Seibert

1996-01-01

188

Macrophages induce COX-2 expression in breast cancer cells: role of IL-1? autoamplification  

PubMed Central

Tumor-associated macrophages and high levels of cyclooxygenase-2 (COX-2) are associated with poor prognosis in breast cancer patients, but their potential interdependence has not been evaluated. The objective of this study was to determine whether macrophages regulate COX-2 expression in breast cancer cells. For this purpose, THP-1 cells were cocultured with HCC1954 breast cancer cells. Coculture led to increased COX-2 expression in the HCC1954 cells and elevated prostaglandin E2 levels in conditioned media. Similar results were observed when THP-1 cells were incubated with HCC1937 breast cancer cells or when human monocyte-derived macrophages were cocultured with HCC1954 cells. Coculture triggered production of reactive oxygen species (ROS) in HCC1954 cells. COX-2 induction was blocked in cells preincubated with an reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor or by silencing p67PHOX, a subunit of NADPH oxidase. ROS production triggered activation of Src and mitogen-activated protein kinases (MAPKs). Blocking Src or MAPK activities or antagonizing the activator protein-1 (AP-1) transcription factor attenuated COX-2 induction in HCC1954 cells. Coculture caused rapid induction of interleukin-1? (IL-1?) in both breast cancer cells and macrophages. Increased IL-1? expression was blocked by an interleukin-1 receptor antagonist (IL-1Ra), suggesting autocrine and paracrine effects. Importantly, macrophage-induced COX-2 expression was blocked in HCC1954 cells preincubated with IL-1Ra or anti-IL-1? IgG. Together, these results indicate that macrophage-mediated induction of COX-2 in breast cancer cells is a consequence of IL-1?-mediated stimulation of ROS?Src?MAPK?AP-1 signaling. IL-1?-dependent induction of COX-2 in breast cancer cells provides a mechanism whereby macrophages contribute to tumor progression and potential therapeutic targets in breast cancer.

Hou, Zhe; Falcone, Domenick J.; Subbaramaiah, Kotha; Dannenberg, Andrew J.

2011-01-01

189

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

PubMed

Increased cyclooxygenase-2 (COX-2) expression is associated with pancreatic ?-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 ?-cell line INS-1 and isolated rat islets to investigate whether Ets-1 could induce ?-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 ?-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 ?-cell dysfunction mediated by COX-2. PMID:24287791

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

2014-08-01

190

Immunohistochemical Evaluation of COX-1 and COX-2 Expression in Keloid and Hypertrophic Scar.  

PubMed

: 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. PMID:24061401

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

2014-04-01

191

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

PubMed Central

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.

2012-01-01

192

Preclinical pharmacology of robenacoxib: a novel selective inhibitor of cyclooxygenase-2.  

PubMed

This manuscript reports the results of preclinical studies in the rat with robenacoxib, a novel selective cyclooxygenase (COX)-2 inhibitor. Robenacoxib selectively inhibited COX-2 in vitro as evidenced from COX-1:COX-2 IC50 ratios of 27:1 in purified enzyme preparations and >967:1 in isolated cell assays. Binding to COX-1 was rapid and readily reversible (dissociation t(1/2) < 1 min), whilst COX-2 binding was slowly reversible (t(1/2) = 25 min). In vivo, robenacoxib inhibited PGE2 production (an index of COX-2 inhibition) in lipopolysaccharide (LPS)-stimulated air pouches (ID50 0.3 mg/kg) and for at least 24 h in zymosan-induced inflammatory exudate (at 2 mg/kg). Robenacoxib was COX-1 sparing, as it inhibited serum TxB2 synthesis ex vivo (an index of COX-1 inhibition) only at very high doses (100 mg/kg but not at 2-30 mg/kg). Robenacoxib inhibited carrageenan-induced paw oedema (ID50 0.40-0.48 mg/kg), LPS-induced fever (ID50 1.1 mg/kg) and Randall-Selitto pain (10 mg/kg). Robenacoxib was highly bound to plasma protein (99.9% at 50 ng/mL in vitro). After intravenous dosing, clearance was 2.4 mL/min/kg and volume of distribution at steady-state was 306 mL/kg. Robenacoxib was preferentially distributed into inflammatory exudate; the AUC for exudate was 2.9 times higher than for blood and the MRT in exudate (15.9 h) was three times longer than in blood (5.3 h). Robenacoxib produced significantly less gastric ulceration and intestinal permeability as compared with the reference nonsteroidal anti-inflammatory drug (NSAID), diclofenac, and did not inhibit PGE2 or 6-keto PGF(1alpha) concentrations in the stomach and ileum at 30 mg/kg. Robenacoxib also had no relevant effects on kidney function at 30 mg/kg. In summary, results of preclinical studies in rats studies suggest that robenacoxib has an attractive pharmacological profile for potential use in the intended target species, cats and dogs. PMID:19161451

King, J N; Dawson, J; Esser, R E; Fujimoto, R; Kimble, E F; Maniara, W; Marshall, P J; O'Byrne, L; Quadros, E; Toutain, P L; Lees, P

2009-02-01

193

A quantitative analysis of kinase inhibitor selectivity  

Microsoft Academic Search

Kinase inhibitors are a new class of therapeutics with a propensity to inhibit multiple targets. The biological consequences of multi-kinase activity are poorly defined, and an important step toward understanding the relationship between selectivity, efficacy and safety is the exploration of how inhibitors interact with the human kinome. We present interaction maps for 38 kinase inhibitors across a panel of

Mazen W Karaman; Sanna Herrgard; Daniel K Treiber; Paul Gallant; Corey E Atteridge; Brian T Campbell; Katrina W Chan; Pietro Ciceri; Mindy I Davis; Philip T Edeen; Raffaella Faraoni; Mark Floyd; Jeremy P Hunt; Daniel J Lockhart; Zdravko V Milanov; Michael J Morrison; Gabriel Pallares; Hitesh K Patel; Stephanie Pritchard; Lisa M Wodicka; Patrick P Zarrinkar

2008-01-01

194

Ovarian hyperstimulation syndrome inhibition by targeting VEGF, COX-2 and Calcium pathways: a preclinical randomized study.  

PubMed

Abstract Objective: The efficacy of vascular endothelial growth factor (VEGF), COX-2, calcium and aromatase inhibitors in an ovarian hyperstimulation syndrome (OHSS) rat model was tested. Methods: One hundred and eight female Wistar rats were randomly divided in nine groups. The control group received saline, while the OHSS group received rec-FSH for 4 consecutive days. The other seven groups received rec-FSH (4d) and Bevacizumab twice, Parecoxib daily, Verapamil daily, Parecoxib daily and Bevacizumab twice, Verapamil daily and Bevacizumab twice, Parecoxib and Verapamil daily, Letrozole and Meloxicam daily, respectively. All groups received also hCG at the 5th day. Results: All intervention groups were characterized by reduced vascular permeability compared to the OHSS group, which in the groups of Verapamil (Calcium inhibition) and Parecoxib?+?Verapamil (COX-2?+?Calcium inhibition) presented significant statistical difference. The Verapamil group showed the lowest corpus luteum formation, while the Parecoxib (COX-2 inhibition), the Parecoxib?+?Verapamil (COX-2?+?Calcium inhibition), the Bevacizumab?+?Parecoxib (VEGF?+?COX-2 inhibition) and the Bevacizumab?+?Verapamil (VEGF?+?Calcium inhibition) groups were also characterized by lower corpus luteum numbers compared to the OHSS group. Furthermore, lower graafian follicle formation was observed in the above groups, while the ovarian weight and the hormonal profile were not significantly affected. Conclusions: Studying the different check points of the VEGF pathway, we conclude that targeting calcium pathways could be beneficial for the vascular permeability control in an OHSS animal model. PMID:24819316

Kitsou, Chrysoula; Kosmas, Ioannis; Lazaros, Leandros; Hatzi, Elissavet; Euaggelou, Aggelos; Mynbaev, Ospan; Tournaye, Herman; Prapas, Nikolaos; Prapas, Ioannis; Zikopoulos, Konstantinos; Galani, Vasiliki; Georgiou, Ioannis

2014-08-01

195

Selective Inhibition of Cyclooxygenase2 by C-Phycocyanin, a Biliprotein from Spirulina platensis  

Microsoft Academic Search

We report data from two related assay systems (isolated enzyme assays and whole blood assays) that C-phycocyanin a biliprotein from Spirulina platensis is a selective inhibitor of cyclooxygenase-2 (COX-2) with a very low IC50 COX-2\\/IC50 COX-1 ratio (0.04). The extent of inhibition depends on the period of preincubation of phycocyanin with COX-2, but without any effect on the period of

C. Madhava Reddy; Vadiraja B. Bhat; G. Kiranmai; M. Narsa Reddy; P. Reddanna; K. M. Madyastha

2000-01-01

196

Oxidative Stress Mediates Chemical Hypoxia- Induced Injury and Inflammation by Activating NF-?b-COX-2 Pathway in HaCaT Cells  

PubMed Central

Hypoxia of skin is an important physiopathological process in many diseases, such as pressure ulcer, diabetic ulcer, and varicose ulcer. Although cellular injury and inflammation have been involved in hypoxia-induced dermatic injury, the underlying mechanisms remain largely unknown. This study was conducted to investigate the effects of cobalt chloride (CoCl2), a hypoxia-mimicking agent, on human skin keratinocytes (HaCaT cells) and to explore the possible molecular mechanisms. Exposure of HaCaT cells to CoCl2 reduced cell viability and caused overproduction of reactive oxygen species (ROS) and oversecretion of interleukin-6 (IL-6) and interleukin-8 (IL-8). Importantly, CoCl2 exposure elicited overexpression of cyclooxygenase-2 (COX-2) and phosphorylation of nuclear factor-kappa B (NF-?B) p65 subunit. Inhibition of COX-2 by NS-398, a selective inhibitor of COX-2, significantly repressed the cytotoxicity, as well as secretion of IL-6 and IL-8 induced by CoCl2. Inhibition of NF-?B by PDTC (a selective inhibitor of NF-?B) or genetic silencing of p65 by RNAi (Si-p65), attenuated not only the cytotoxicity and secretion of IL-6 and IL-8, but also overexpression of COX- 2 in CoCl2-treated HaCaT cells. Neutralizing anti-IL-6 or anti-IL-8 antibody statistically alleviated CoCl2-induced cytotoxicity in HaCaT cells. N-acetyl-L-cysteine (NAC), a well characterized ROS scavenger, obviously suppressed CoCl2-induced cytotoxicity in HaCaT cells, as well as secretion of IL-6 and IL-8. Additionally, NAC also repressed overexpression of COX-2 and phosphorylation of NF-?B p65 subunit induced by CoCl2 in HaCaT cells. In conclusion, our results demonstrated that oxidative stress mediates chemical hypoxia-induced injury and inflammatory response through activation of NF-?B–COX-2 pathway in HaCaT cells.

Yang, Chuntao; Ling, Hongzhong; Zhang, Meifen; Yang, Zhanli; Wang, Xiuyu; Zeng, Fanqin; Wang, Chuhuai; Feng, Jianqiang

2011-01-01

197

Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Cytotoxicity and Inflammation in HaCaT Cells through Inhibition of ROS/NF-?B/COX-2 Pathway  

PubMed Central

Hydrogen sulfide (H2S) has been shown to protect against oxidative stress injury and inflammation in various hypoxia-induced insult models. However, it remains unknown whether H2S protects human skin keratinocytes (HaCaT cells) against chemical hypoxia-induced damage. In the current study, HaCaT cells were treated with cobalt chloride (CoCl2), a well known hypoxia mimetic agent, to establish a chemical hypoxia-induced cell injury model. Our findings showed that pretreatment of HaCaT cells with NaHS (a donor of H2S) for 30 min before exposure to CoCl2 for 24 h significantly attenuated CoCl2-induced injuries and inflammatory responses, evidenced by increases in cell viability and GSH level and decreases in ROS generation and secretions of IL-1?, IL-6 and IL-8. In addition, pretreatment with NaHS markedly reduced CoCl2-induced COX-2 overexpression and PGE2 secretion as well as intranuclear NF-?B p65 subunit accumulation (the central step of NF-?B activation). Similar to the protective effect of H2S, both NS-398 (a selective COX-2 inhibitor) and PDTC (a selective NF-?B inhibitor) depressed not only CoCl2-induced cytotoxicity, but also the secretions of IL-1?, IL-6 and IL-8. Importantly, PDTC obviously attenuated overexpression of COX-2 induced by CoCl2. Notably, NAC, a ROS scavenger, conferred a similar protective effect of H2S against CoCl2-induced insults and inflammatory responses. Taken together, the findings of the present study have demonstrated for the first time that H2S protects HaCaT cells against CoCl2-induced injuries and inflammatory responses through inhibition of ROS-activated NF-?B/COX-2 pathway.

Dong, Qi; Wang, Xiuyu; Lan, Aiping; Zeng, Fanqin; Chen, Peixi; Wang, Chuhuai; Feng, Jianqiang

2011-01-01

198

Upregulation of COX-2 in the lung cancer promotes overexpression of multidrug resistance protein 4 (MRP4) via PGE2-dependent pathway.  

PubMed

It is apparent that lung cancer is associated with inflammation, with accompanying hallmark elevations of cyclooxygenase 2 (COX-2) and prostaglandin E2 (PGE2) levels. However, the effects of these changes on MRP efflux transporters have not been thoroughly investigated before. Here, we report that upregulation of COX-2 can induce overexpression of MRP4 in both A549 non-small-cell lung cancer cell lines and mouse lung cancer models. In A549 cells, phorbol 12-myristate 13-acetate (PMA) treatment induced upregulation of COX-2 and MRP4 together, but not other MRP transporters. Transient overexpression of human COX-2 cDNA also specifically increased COX-2 and MRP4. Moreover, COX inhibitor treatment and COX-2-specific siRNA significantly inhibited the upregulation of MRP4. Additionally, PMA-treatment increased extracellular PGE2 levels, likely due to increased MRP4 function. Likewise, COX-2-specific siRNA reduced extracellular PGE2 levels. Furthermore, COX-2 upregulation resulted in an increase in mPGES-1, an enzyme responsible for PGE2 production. Finally, metastasized lung cancer model mice exhibited increased expression levels of COX-2 and MRP4, as well as mPGES-1. In conclusion, the present study suggests that overexpression of MRP4 in lung cancer may be attributable to COX-2 upregulation via a PGE2-dependent pathway. PMID:24909729

Maeng, Han-Joo; Lee, Wook-Joo; Jin, Qing-Ri; Chang, Ji-Eun; Shim, Won-Sik

2014-10-01

199

Synthesis and evaluation of dithiolethiones as novel cyclooxygenase inhibitors.  

PubMed

3H-1,2-Dithiole-3-thiones substituted with a 3,5-di-tert-butyl-4-hydroxyphenyl (DTBHP) or a 3,5-di-tert-butyl-4-methoxyphenyl group at the C5 position were prepared and their ability to inhibit the cyclooxygenase isoenzymes, COX-1 and COX-2 was evaluated. Both compounds were potent inhibitors of COX-2 (relative to rofecoxib), and while the phenol was a weak inhibitor of COX-1, the methyl ether gave no measurable inhibition. Docking studies of the two compounds into the COX-1 and -2 active sites showed that the methyl ether could only fit in the COX-2 active site whereas the phenol could be docked into both COX-1 and -2. This study reports a new mode for inhibitor binding to COX-1 and -2 and a novel structural scaffold for the development of COX-2 selective inhibitors. PMID:19056264

Zanatta, Shannon D; Manallack, David T; Jarrott, Bevyn; Williams, Spencer J

2009-01-15

200

Postoperative Administration of the Analgesic Tramadol, but Not the Selective Cyclooxygenase2 Inhibitor Parecoxib, Abolishes Postoperative Hyperalgesia in a New Model of Postoperative Pain in Rats  

Microsoft Academic Search

Background\\/Aims: Using a new animal model of postoperative pain we recently developed, we investigated whether the selective cyclooxygenase-2 (COX-2) inhibitor pare-coxib sodium, and the analgesic tramadol hydrochloride, attenuated mechanical primary hyperalgesia induced by minor surgery on the rat tail. Methods: For surgery, rats were anesthetized with isoflurane, a 20-mm-long incision was made through the skin and fascia of their tails,

Peter Kamerman; Anthony Koller; Lisa Loram

2007-01-01

201

Inhibition of COX-2 expression by topical diclofenac enhanced radiation sensitivity via enhancement of TRAIL in human prostate adenocarcinoma xenograft model  

PubMed Central

Background COX-2 inhibitors have an antitumor potential and have been verified by many researchers. Treatment of cancer cells with external stressors such as irradiation can stimulate the over-expression of COX-2 and possibly confer radiation resistance. In this study, we tested if topical diclofenac, which inhibits both COX-1 and COX-2, administration rendered prostate tumor cells sensitize to the effects of radiation. Methods LNCaP-COX-2 and LNCaP-Neo cells were treated with 0 to 1000 ?M diclofenac. Next, a clonogenic assay was performed in which cells were subjected to irradiation (0 to 4 Gy) with or without diclofenac. COX-2 expression and other relevant molecules were measured by real-time PCR and immunohistochemistry after irradiation and diclofenac treatment. In addition, we assessed the tumor volumes of xenograft LNCaP-COX-2 cells treated with topical diclofenac with or without radiation therapy (RT). Results LNCaP-COX-2 and LNCaP-Neo cell lines experienced cytotoxic effects of diclofenac in a dose related manner. Clonogenic assays demonstrated that LNCaP-COX-2 cells were significantly more resistant to RT than LNCaP-Neo cells. Furthermore, the addition of diclofenac sensitized LNCaP-COX-2 not but LNCaP-Neo cells to the cytocidal effects of radiation. In LNCaP-COX-2 cells, diclofenac enhanced radiation-induced apoptosis compared with RT alone. This phenomenon might be attributed to enhancement of RT-induced TRAIL expression as demonstrated by real-time PCR analysis. Lastly, tumor volumes of LNCaP-COX-2 cells xenograft treated with diclofenac or RT alone was >4-fold higher than in mice treated with combined diclofenac and radiation (p<0.05). Conclusions These in vitro and in vivo findings suggest that conventional COX inhibitor, diclofenac enhances the effect of RT on prostate cancer cells that express COX-2. Thus, diclofenac may have potential as radiosensitizer for treatment of prostate cancer.

2013-01-01

202

Selective cyclooxygenase-2 silencing mediated by engineered E. coli and RNA interference induces anti-tumour effects in human colon cancer cells  

PubMed Central

Background: Cyclooxygenase-2 (COX-2) overexpression is strongly associated with colorectal tumourigenesis. It has been demonstrated that the chronic use of non-steroidal anti-inflammatory drugs (COX inhibitors) partially protects patients from colorectal cancer (CRC) development and progression but induces severe cardiovascular side effects. New strategies for selective COX-2 blockade are required. Methods: We developed an improved technique, based on RNA interference (RNAi), to gain a selective COX-2 silencing in CRC cells by a tumour-dependent expression of anti-COX-2 short-hairpin RNA (shCOX-2). Anti-COX-2 shRNA-expressing vectors were delivered in CRC cells (in vitro) and in colon tissues (ex vivo) using engineered Escherichia coli strains, capable of invading tumour cells (InvColi). Results: A highly tumour-dependent shCOX-2 expression and a significant COX-2 silencing were observed in CRC cells following InvColi strain infection. Cyclooxygenase-2 silencing was associated with a strong reduction in both proliferative and invasive behaviour of tumour cells. We also demonstrated a pivotal role of COX-2 overexpression for the survival of CRC cells after bacterial infection. Moreover, COX-2 silencing was achieved ex vivo by infecting colon tissue samples with InvColi strains, leading to anti-inflammatory and anti-tumour effects. Conclusion: Our RNAi/InvColi-mediated approach offers a promising tool for a highly selective COX-2 blockade in vitro and in vivo.

Strillacci, A; Griffoni, C; Lazzarini, G; Valerii, M C; Di Molfetta, S; Rizzello, F; Campieri, M; Moyer, M P; Tomasi, V; Spisni, E

2010-01-01

203

Cyclooxygenase-2 (COX-2) inhibition constrains indoleamine 2,3-dioxygenase 1 (IDO1) activity in acute myeloid leukaemia cells.  

PubMed

Indoleamine 2,3-dioxygenase 1 (IDO1) metabolizes L-tryptophan to kynurenines (KYN), inducing T-cell suppression either directly or by altering antigen-presenting-cell function. Cyclooxygenase (COX)-2, the rate-limiting enzyme in the synthesis of prostaglandins, is over-expressed by several tumours. We aimed at determining whether COX-2 inhibitors down-regulate the IFN-g-induced expression of IDO1 in acute myeloid leukaemia (AML) cells. IFN-? at 100 ng/mL up-regulated COX-2 and IDO1 in HL-60 AML cells, both at mRNA and protein level. The increased COX-2 and IDO1 expression correlated with heightened production of prostaglandin (PG)E? and kynurenines, respectively. Nimesulide, a preferential COX-2 inhibitor, down-regulated IDO1 mRNA/protein and attenuated kynurenine synthesis, suggesting that overall IDO inhibition resulted both from reduced IDO1 gene transcription and from inhibited IDO1 catalytic activity. From a functional standpoint, IFN-g-challenged HL-60 cells promoted the in vitro conversion of allogeneic CD4?CD25? T cells into bona fide CD4?CD25?FoxP3? regulatory T cells, an effect that was significantly reduced by treatment of IFN-?-activated HL-60 cells with nimesulide. Overall, these data point to COX-2 inhibition as a potential strategy to be pursued with the aim at circumventing leukaemia-induced, IDO-mediated immune dysfunction. PMID:23973990

Iachininoto, Maria Grazia; Nuzzolo, Eugenia Rosa; Bonanno, Giuseppina; Mariotti, Andrea; Procoli, Annabella; Locatelli, Franco; De Cristofaro, Raimondo; Rutella, Sergio

2013-01-01

204

Adenovirus type 5 E1A-induced apoptosis in COX-2-overexpressing breast cancer cells  

PubMed Central

Introduction Suppression of Bcl-2 expression can overcome cellular resistance to apoptosis induced by the adenovirus type 5 gene E1A in models of ovarian and breast cancer. Celecoxib, a cyclooxygenase-2 (COX-2) inhibitor, is known to downregulate Bcl-2 expression. We hypothesized that celecoxib would enhance E1A-induced apoptosis by suppressing Bcl-2 through suppressing COX-2 expression. If successful, this strategy could represent a means of overcoming resistance to E1A gene therapy. Methods We first established the cytotoxicity of celecoxib in two COX-2-overexpressing E1A-transfected breast cancer cell lines (MDA-MB-231 and MDA-MB-435) and in two low-COX-2-expressing E1A-transfected cell lines (MCF-7 (breast cancer) and SKOV3.ip1 (ovarian cancer)). We next tested whether higher sensitivity to celecoxib among these cell lines resulted from increased apoptosis by flow cytometry and western blotting. We further investigated whether suppression of Bcl-2 by celecoxib was involved in the apoptosis resulting from celecoxib treatment, and we explored whether the celecoxib-induced apoptosis in these cells depends on a COX-2 downstream pathway. Results The two COX-2-overexpressing cell lines MDA-MB-231-E1A and MDA-MB-435-E1A were more sensitive to celecoxib than the corresponding control cells, but the two low-COX-2-expressing cell lines MCF-7-E1A and SKOV3.ip1-E1A were no more sensitive than control cells to celecoxib. Therefore, we used the MDA-MB-231-E1A and MDA-MB-435-E1A cells for all further experiments. In both cell lines, sub-G1 fraction was increased, or cleavage of PARP and caspase-9 were increased after 5 days of exposure to 40 ?M celecoxib. However, Bcl-2 was suppressed only in the MDA-MB-435-E1A cells and not in the MDA-MB-231-E1A cells. Restoring Bcl-2 expression in the MDA-MB-435-E1A stable transfectants did not affect their sensitivity to celecoxib. However, adding prostaglandin E2 (PGE2) or PGF2? blunted the sensitivity to celecoxib of both E1A stable transfectants. Conclusion We speculate that one mechanism by which celecoxib enhances E1A-induced apoptosis in cells that express high levels of COX-2 is through blocking PGE2 or PGF2?.

Sugimoto, Takeshi; Bartholomeusz, Chandra; Tari, Ana M; Ueno, Naoto T

2007-01-01

205

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

PubMed

1. 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. 2. Infusion of LPS to rats for 6 h caused a time-dependent increase in the plasma concentrations of 6 keto-prostaglandin F1alpha (6 keto-PGF1alpha) 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-PGF1alpha in LPS-treated animals. 3. Treatment of rats with 1400W or the non-selective NOS inhibitor N(G)-monomethyl-L-arginine (L-NMMA) inhibited the increase in plasma NO2/NO3 but were both without effect on the plasma concentration of 6 keto-PGF1alpha before or after AA. 4. Treatment with the non-steroidal anti-inflammatory drugs (NSAIDs), A771726 or diclofenac, or with celecoxib significantly reduced the increase in circulating 6 keto-PGF1alpha caused by LPS, and the large increase in 6 keto-PGF1alpha 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-PGF1alpha and the increase in NO2/NO3. 5. In conclusion, the use of selective inhibitors does not support the concept of cross talk in vivo between iNOS and COX-2. PMID:9786506

Hamilton, L C; Warner, T D

1998-09-01

206

Directed Apoptosis in COX-2 Overexpressing Cancer Cells Through Expression Targeting Gene Delivery.  

National Technical Information Service (NTIS)

The present invention provides methods and constructs for selectively expressing an Apoptosis-Inducing Gene (AIG) in a population of cells that overexpress cyclooxygenase-2 (COX-2) to induce apoptosis in the cell. To achieve this goal a chimeric gene cons...

A. Atala W. T. Godbey

2004-01-01

207

Kaposi's Sarcoma Associated Herpes Virus (KSHV) Induced COX-2: A Key Factor in Latency, Inflammation, Angiogenesis, Cell Survival and Invasion  

PubMed Central

Kaposi's sarcoma (KS), an enigmatic endothelial cell vascular neoplasm, is characterized by the proliferation of spindle shaped endothelial cells, inflammatory cytokines (ICs), growth factors (GFs) and angiogenic factors. KSHV is etiologically linked to KS and expresses its latent genes in KS lesion endothelial cells. Primary infection of human micro vascular endothelial cells (HMVEC-d) results in the establishment of latent infection and reprogramming of host genes, and cyclooxygenase-2 (COX-2) is one of the highly up-regulated genes. Our previous study suggested a role for COX-2 in the establishment and maintenance of KSHV latency. Here, we examined the role of COX-2 in the induction of ICs, GFs, angiogenesis and invasive events occurring during KSHV de novo infection of endothelial cells. A significant amount of COX-2 was detected in KS tissue sections. Telomerase-immortalized human umbilical vein endothelial cells supporting KSHV stable latency (TIVE-LTC) expressed elevated levels of functional COX-2 and microsomal PGE2 synthase (m-PGES), and secreted the predominant eicosanoid inflammatory metabolite PGE2. Infected HMVEC-d and TIVE-LTC cells secreted a variety of ICs, GFs, angiogenic factors and matrix metalloproteinases (MMPs), which were significantly abrogated by COX-2 inhibition either by chemical inhibitors or by siRNA. The ability of these factors to induce tube formation of uninfected endothelial cells was also inhibited. PGE2, secreted early during KSHV infection, profoundly increased the adhesion of uninfected endothelial cells to fibronectin by activating the small G protein Rac1. COX-2 inhibition considerably reduced KSHV latent ORF73 gene expression and survival of TIVE-LTC cells. Collectively, these studies underscore the pivotal role of KSHV induced COX-2/PGE2 in creating KS lesion like microenvironment during de novo infection. Since COX-2 plays multiple roles in KSHV latent gene expression, which themselves are powerful mediators of cytokine induction, anti-apoptosis, cell survival and viral genome maintainence, effective inhibition of COX-2 via well-characterized clinically approved COX-2 inhibitors could potentially be used in treatment to control latent KSHV infection and ameliorate KS.

Sharma-Walia, Neelam; Sadagopan, Sathish; Veettil, Mohanan Valiya; Kerur, Nagaraj; Chandran, Bala

2010-01-01

208

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

SciTech Connect

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.

Magari, Hirohito [Second Dept. of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Shimizu, Yasuhito [Second Dept. of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Inada, Ken-ichi [First Dept. of Pathology, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192 (Japan); Enomoto, Shotaro [Second Dept. of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Tomeki, Tatsuji [Second Dept. of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Yanaoka, Kimihiko [Second Dept. of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Tamai, Hideyuki [Second Dept. of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Arii, Kenji [Second Dept. of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Nakata, Hiroya [Second Dept. of Internal Medicine, Wakayama Medical Univ., 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Oka, Masashi [Second Dept. of Internal Medicine, Wakayama Medical Univ., 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Utsunomiya, Hirotoshi [Dept. of Pathology, Wakayama Medical Univ., 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan); Tsutsumi, Yutaka [First Dept. of Pathology, Fujita Health Univ. School of Medicine, Toyoake, Aichi 470-1192 (Japan); Tsukamoto, Tetsuya [Lab. of Pathology, Aichi Cancer Center Research Inst., Aichi 464-8681 (Japan); Tatematsu, Masae [Lab. of Pathology, Aichi Cancer Center Research Inst., Aichi 464-8681 (Japan); Ichinose, Masao [Second Dept. of Internal Medicine, Wakayama Medical Univ., 811-1 Kimiidera, Wakayama-City, Wakayama 641-0012 (Japan)] E-mail: ichinose@wakayama-med.ac.jp

2005-08-26

209

p50-associated COX-2 extragenic RNA (PACER) activates COX-2 gene expression by occluding repressive NF-?B complexes  

PubMed Central

Deregulated expression of COX-2 has been causally linked to development, progression, and outcome of several types of human cancer. We describe a novel fundamental level of transcriptional control of COX-2 expression. Using primary human mammary epithelial cells and monocyte/macrophage cell lines, we show that the chromatin boundary/insulator factor CTCF establishes an open chromatin domain and induces expression of a long non-coding RNA within the upstream promoter region of COX-2. Upon induction of COX-2 expression, the lncRNA associates with p50, a repressive subunit of NF-?B, and occludes it from the COX-2 promoter, potentially facilitating interaction with activation-competent NF-?B p65/p50 dimers. This enables recruitment of the p300 histone acetyltransferase, a domain-wide increase in histone acetylation and assembly of RNA Polymerase II initiation complexes. Our findings reveal an unexpected mechanism of gene control by lncRNA-mediated repressor occlusion and identify the COX-2-lncRNA, PACER, as a new potential target for COX-2-modulation in inflammation and cancer. DOI: http://dx.doi.org/10.7554/eLife.01776.001

Krawczyk, Michal; Emerson, Beverly M

2014-01-01

210

COX-2/PGE2: molecular ambassadors of Kaposi's sarcoma-associated herpes virus oncoprotein-v-FLIP  

PubMed Central

Kaposi's sarcoma herpesvirus (KSHV) latent oncoprotein viral FLICE (FADD-like interferon converting enzyme)-like inhibitory protein (v-FLIP) or K13, a potent activator of NF-?B, has well-established roles in KSHV latency and oncogenesis. KSHV-induced COX-2 represents a novel strategy employed by KSHV to promote latency and inflammation/angiogenesis/invasion. Here, we demonstrate that v-FLIP/K13 promotes tumorigenic effects via the induction of host protein COX-2 and its inflammatory metabolite PGE2 in an NF-?B-dependent manner. In addition to our previous studies demonstrating COX-2/PGE2's role in transcriptional regulation of KSHV latency promoter and latent gene expression, the current study adds to the complexity that though LANA-1 (latency associated nuclear antigen) is utilizing COX-2/PGE2 as critical factors for its transcriptional regulation, it is the v-FLIP/K13 gene in the KSHV latency cluster that maintains continuous COX-2/PGE2 levels in the infected cells. We demonstrate that COX-2 inhibition, via its chemical inhibitors (NS-398 or celecoxib), reduced v-FLIP/K13-mediated NF-?B induction, and extracellular matrix (ECM) interaction-mediated signaling, mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) levels, and subsequently downregulated detachment-induced apoptosis (anoikis) resistance. vFLIP expression mediated the secretion of cytokines, and spindle cell differentiation activated the phosphorylation of p38, RSK, FAK, Src, Akt and Rac1-GTPase. The COX-2 inhibition in v-FLIP/K13-HMVECs reduced inflammation and invasion/metastasis-related genes, along with reduced anchorage-independent colony formation via modulating ‘extrinsic' as well as ‘intrinsic' cell death pathways. COX-2 blockade in v-FLIP/K13-HMVEC cells drastically augmented cell death induced by removal of essential growth/survival factors secreted in the microenvironment. Transformed cells obtained from anchorage-independent colonies of COX-2 inhibitor-treated v-FLIP/K13-HMVEC cells expressed lower levels of endothelial–mesenchymal transition genes such as slug, snail and twist, and higher expression of the tumor-suppressor gene, E-cadherin. Taken together, our study provides strong evidences that FDA-approved COX-2 inhibitors have great potential in blocking tumorigenic events linked to KSHV's oncogenic protein v-FLIP/K13.

Sharma-Walia, N; Patel, K; Chandran, K; Marginean, A; Bottero, V; Kerur, N; Paul, A G

2012-01-01

211

COX2-mediated Inflammation in Fat Is Crucial for Obesity-linked Insulin Resistance and Fatty Liver  

Microsoft Academic Search

The aim was to examine the role of cyclooxygenase (COX)-2-mediated inflammation in the development of obese linked insulin resistance and fatty liver. The rats were fed separately regular diet (CONT), high-fat diet (HFD) ad libitum, or energy restrictedly for 12 weeks. Rats fed HFD ad libitum were further divided into three subgroups co-treated with vehicle (HFa), or a selective COX-2

Po-Shiuan Hsieh; Jong-Shiaw Jin; Chih-Fan Chiang; Pei-Chi Chan; Chih-Hao Chen; Kuang-Chung Shih

2009-01-01

212

Novel COX-2 Inhibitor for Breast Cancer Therapy.  

National Technical Information Service (NTIS)

Recent studies have shown that NSAIDS such as aspirin reduce the incidence of human cancers by inhibiting the enzyme Cyclooxygenase (COX), which plays a key role in arachidonic acid metabolism. It is now known that COX exists in at leas two isoforms, term...

E. P. Reddy

2003-01-01

213

Regulation of COX-2 expression and IL-6 release by particulate matter in airway epithelial cells.  

PubMed

Particulate matter (PM) in ambient air is a risk factor for human respiratory and cardiovascular diseases. The delivery of PM to airway epithelial cells has been linked to release of proinflammatory cytokines; however, the mechanisms of PM-induced inflammatory responses are not well-characterized. This study demonstrates that PM induces cyclooxygenase (COX)-2 expression and IL-6 release through both a reactive oxygen species (ROS)-dependent NF-kappaB pathway and an ROS-independent C/EBPbeta pathway in human bronchial epithelial cells (HBEpCs) in culture. Treatment of HBEpCs with Baltimore PM induced ROS production, COX-2 expression, and IL-6 release. Pretreatment with N-acetylcysteine (NAC) or EUK-134, in a dose-dependent manner, attenuated PM-induced ROS production, COX-2 expression, and IL-6 release. The PM-induced ROS was significantly of mitochondrial origin, as evidenced by increased oxidation of the mitochondrially targeted hydroethidine to hydroxyethidium by reaction with superoxide. Exposure of HBEpCs to PM stimulated phosphorylation of NF-kappaB and C/EBPbeta, while the NF-kappaB inhibitor, Bay11-7082, or C/EBPbeta siRNA attenuated PM-induced COX-2 expression and IL-6 release. Furthermore, NAC or EUK-134 attenuated PM-induced activation of NF-kappaB; however, NAC or EUK-134 had no effect on phosphorylation of C/EBPbeta. In addition, inhibition of COX-2 partly attenuated PM-induced Prostaglandin E2 and IL-6 release. PMID:18617679

Zhao, Yutong; Usatyuk, Peter V; Gorshkova, Irina A; He, Donghong; Wang, Ting; Moreno-Vinasco, Liliana; Geyh, Alison S; Breysse, Patrick N; Samet, Jonathan M; Spannhake, Ernst Wm; Garcia, Joe G N; Natarajan, Viswanathan

2009-01-01

214

Identification of [4-[4-(methylsulfonyl)phenyl]-6-(trifluoromethyl)-2-pyrimidinyl] amines and ethers as potent and selective cyclooxygenase-2 inhibitors  

Microsoft Academic Search

A novel series of [4-[4-(methylsulfonyl)phenyl]-6-(trifluoromethyl)-2-pyrimidine-based cyclooxygenase-2 (COX-2) inhibitors, which have a different arrangement of substituents compared to the more common 1,2-diarylheterocycle based molecules, have been discovered. For example, 2-(butyloxy)-4-[4-(methylsulfonyl)phenyl]-6-(trifluoromethyl)pyrimidine (47), a member of the 2-pyrimidinyl ether series, has been shown to be a potent and selective inhibitor with a favourable pharmacokinetic profile, high brain penetration and good efficacy in rat

Martin E. Swarbrick; Paul J. Beswick; Robert J. Gleave; Richard H. Green; Sharon Bingham; Chas Bountra; Malcolm C. Carter; Laura J. Chambers; Iain P. Chessell; Nick M. Clayton; Sue D. Collins; John A. Corfield; C. David Hartley; Savvas Kleanthous; Paul F. Lambeth; Fiona S. Lucas; Neil Mathews; Alan Naylor; Lee W. Page; Jeremy J. Payne; Neil A. Pegg; Helen S. Price; John Skidmore; Alexander J. Stevens; Richard Stocker; Sharon C. Stratton; Alastair J. Stuart; Joanne O. Wiseman

2009-01-01

215

Selective inhibitors of picornavirus replication.  

PubMed

Picornaviruses cover a large family of pathogens that have a major impact on human but also on veterinary health. Although most infections in man subside mildly or asymptomatically, picornaviruses can also be responsible for severe, potentially life-threatening disease. To date, no therapy has been approved for the treatment of picornavirus infections. However, efforts to develop an antiviral that is effective in treating picornavirus-associated diseases are ongoing. In 2007, Schering-Plough, under license of ViroPharma, completed a phase II clinical trial with Pleconaril, a drug that was originally rejected by the FDA after a New Drug Application in 2001. Rupintrivir, a rhinovirus protease inhibitor developed at Pfizer, reached clinical trials but was recently halted from further development. Finally, Biota's HRV drug BTA-798 is scheduled for phase II trials in 2008. Several key steps in the picornaviral replication cycle, involving structural as well as non-structural proteins, have been identified as valuable targets for inhibition. The current review aims to highlight the most important developments during the past decades in the search for antivirals against picornaviruses. PMID:18381747

De Palma, Armando M; Vliegen, Inge; De Clercq, Erik; Neyts, Johan

2008-11-01

216

Discovery of histone deacetylase 8 selective inhibitors  

PubMed Central

We have developed an efficient method for synthesizing candidate histone deacetylase (HDAC) inhibitors in 96-well plates, which are used directly in high-throughput screening. We selected building blocks having hydrazide, aldehyde and hydroxamic acid functionalities. The hydrazides were coupled with different aldehydes in DMSO. The resulting products have the previously identified ‘cap/linker/biasing element’ structure known to favor inhibition of HDACs. These compounds were assayed without further purification. HDAC8-selective inhibitors were discovered from this novel collection of compounds.

Tang, Weiping; Luo, Tuoping; Greenberg, Edward F.; Bradner, James E.; Schreiber, Stuart L.

2012-01-01

217

UVB-induced COX-2 expression requires histone H3 phosphorylation at Ser10 and Ser28  

PubMed Central

Cyclooxygenase-2 (COX-2) is an inducible enzyme that contributes to the generation of chronic inflammation in response to chemical carcinogens and environmental stresses, including ultraviolet B (UVB) irradiation. Although post-translational histone modifications are believed to play an important role in modulating transcriptional regulation of UVB-induced COX-2, the underlying biochemical mechanisms are completely unknown. Here, we show that UVB activates the p38 MAPK/MSK1 kinase cascade to phosphorylate histone H3 at Ser10 and Ser28, contributing to UVB-induced COX-2 expression. UVB has no effect on the global trimethylation level of histone H3 (H3K4me3, H3K9me3, and H3K27me3). We observed that selected mammalian 14-3-3 proteins bind to UVB-induced phosphorylated histone H3 (Ser10 and Ser28). In particular, 14-3-3? is critical for recruiting MSK1 and Cdk9 to the chromatin and subsequently phosphorylating the C-terminal domain (CTD) of RNA polymerase II in the cox-2 promoter. We propose that histone H3 phosphorylation at Ser10 and Ser28 serve as critical switches to promote cox-2 gene expression by facilitating the recruitment of MSK1 and Cdk9 to the cox-2 promoter, thereby promoting RNA polymerase II phosphorylation.

Keum, Young-Sam; Kim, Hong-Gyum; Bode, Ann M.; Surh, Young-Joon; Dong, Zigang

2012-01-01

218

Selective inhibitors of biosynthesis of aminergic neurotransmitters  

Microsoft Academic Search

ALTHOUGH the enzymatic decarboxylation of amino acids is of substantial importance to biochemistry1, there are few inhibitors of the decarboxylase enzymes which combine activity with selectivity. Several of the amines formed by in vivo decarboxylation of amino acids (biogenic amines) have key roles in physiology. The neurotransmitters dopamine, 5-hydroxytryptamine, histamine and gamma-aminobutyric acid result from such enzymatic decarboxylation; dopamine in

J. Kollonitsch; A. A. Patchett; S. Marburg; A. L. Maycock; L. M. Perkins; G. A. Doldouras; D. E. Duggan; S. D. Aster

1978-01-01

219

COX-2 in the neurodegenerative process of Parkinson's disease  

PubMed Central

The enzyme cyclooxygenase-2 (COX-2), responsible for the first committed step in the synthesis of several important mediators which are involved in both initiation and resolution of inflammation, and the subsequent generation of prostaglandins (PGs) upon activation has been shown to participate in the neurodegenerative processes of a variety of diseases. This review looks particular at the role of COX-2 in the pathogenesis of Parkinson's disease, involving the generation of PGs and the role of the two different parts of the cyclooxygenase—cyclooxygenase and peroxidase activity.

Teismann, Peter

2012-01-01

220

Promoter scanning of the Human COX-2 gene with 8-ring polyamides: unexpected weakening of polyamide-DNA binding and selectivity by replacing an internal N-Me-pyrrole with ?-alanine  

PubMed Central

Rules for polyamide DNA recognition have proved invaluable for the design of sequence-selective DNA-binding agents in cell-free systems. However, these rules are not fully transferrable to predicting activity in cells, tissues or animals, and additional refinements to our understanding of DNA recognition would help biomedical studies. Similar complexities are encountered when using internal ?-alanines as polyamide building blocks in place of N-methyl pyrrole; ?-alanines were introduced in polyamide designs to maintain good hydrogen bonding registry with the target DNA, especially for long polyamides or those with several GC bp (P.B. Dervan, A.R. Urbach, Essays Contemp. Chem. (2001) 327–339). Thus, to clarify important subtleties of molecular recognition, we studied the effects of replacing a single pyrrole with ?-alanine in 8-ring polyamides designed against the Ets-1 transcription factor. Replacement of a single internal N-methylpyrrole with ?-alanine to generate a ?/Im pairing in two 8-ring polyamides causes a decrease in DNA binding affinity by two orders of magnitude and decreases DNA binding selectivity, contrary to expectations based on the literature. Measurements were made by fluorescence spectroscopy, quantitative DNA footprinting and surface plasmon resonance, with these vastly different techniques showing excellent agreement. Furthermore, results were validated for a range of DNA substrates from small hairpins to long dsDNA sequences. Docking studies helped show that ?-alanine does not make efficient hydrophobic contacts with the rest of the polyamide or nearby DNA, in contrast to pyrrole. These results help refine design principles and expectations for polyamide-DNA recognition.

Aston, Karl; Ramos, Joseph P.; Koeller, Kevin J.; Nanjunda, Rupesh; He, Gaofei

2012-01-01

221

Promoter scanning of the human COX-2 gene with 8-ring polyamides: unexpected weakening of polyamide-DNA binding and selectivity by replacing an internal N-Me-pyrrole with ?-alanine.  

PubMed

Rules for polyamide-DNA recognition have proved invaluable for the design of sequence-selective DNA binding agents in cell-free systems. However, these rules are not fully transferrable to predicting activity in cells, tissues or animals, and additional refinements to our understanding of DNA recognition would help biomedical studies. Similar complexities are encountered when using internal ?-alanines as polyamide building blocks in place of N-methylpyrrole; ?-alanines were introduced in polyamide designs to maintain good hydrogen bonding registry with the target DNA, especially for long polyamides or those with several GC bp (P.B. Dervan, A.R. Urbach, Essays Contemp. Chem. (2001) 327-339). Thus, to clarify important subtleties of molecular recognition, we studied the effects of replacing a single pyrrole with ?-alanine in 8-ring polyamides designed against the Ets-1 transcription factor. Replacement of a single internal N-methylpyrrole with ?-alanine to generate a ?/Im pairing in two 8-ring polyamides causes a decrease in DNA binding affinity by two orders of magnitude and decreases DNA binding selectivity, contrary to expectations based on the literature. Measurements were made by fluorescence spectroscopy, quantitative DNA footprinting and surface plasmon resonance, with these vastly different techniques showing excellent agreement. Furthermore, results were validated for a range of DNA substrates from small hairpins to long dsDNA sequences. Docking studies helped show that ?-alanine does not make efficient hydrophobic contacts with the rest of the polyamide or nearby DNA, in contrast to pyrrole. These results help refine design principles and expectations for polyamide-DNA recognition. PMID:23023196

Bashkin, James K; Aston, Karl; Ramos, Joseph P; Koeller, Kevin J; Nanjunda, Rupesh; He, Gaofei; Dupureur, Cynthia M; David Wilson, W

2013-02-01

222

Inhibitory effects of selective cyclooxygenase-2 inhibitors, nimesulide and etodolac, on the development of squamous cell dysplasias and carcinomas of the tongue in rats initiated with 4-nitroquinoline 1-oxide  

Microsoft Academic Search

The present study was conducted to examine the effects of selective cyclooxygenase (COX)-2 inhibitors, nimesulide and etodolac, on early stages of tongue carcinogenesis due to 4-nitroquinoline 1-oxide(4-NQO). Fischer 344 rats, 6 weeks old, were given 15 ppm of 4-NQO in their drinking water for 8 weeks followed by diet containing either nimesulide or etodolac at the doses of 150 and

Kazuhiko Yamamoto; Wakashi Kitayama; Ayumi Denda; Ayumu Morisaki; Hiroki Kuniyasu; Tadaaki Kirita

2003-01-01

223

Resveratrol Targeting of Carcinogen-Induced Brain Endothelial Cell Inflammation Biomarkers MMP-9 and COX-2 is Sirt1-Independent  

PubMed Central

The occurrence of a functional relationship between the release of metalloproteinases (MMPs) and the expression of cyclooxygenase (COX)-2, two inducible pro-inflammatory biomarkers with important pro-angiogenic effects, has recently been inferred. While brain endothelial cells play an essential role as structural and functional components of the blood-brain barrier (BBB), increased BBB breakdown is thought to be linked to neuroinflammation. Chemopreventive mechanisms targeting both MMPs and COX-2 however remain poorly investigated. In this study, we evaluated the pharmacological targeting of Sirt1 by the diet-derived and antiinflammatory polyphenol resveratrol. Total RNA, cell lysates, and conditioned culture media from human brain microvascular endothelial cells (HBMEC) were analyzed using qRT-PCR, immunoblotting, and zymography respectively. Tissue scan microarray analysis of grade I–IV brain tumours cDNA revealed increased gene expression of Sirt-1 from grade I–III but surprisingly not in grade IV brain tumours. HBMEC were treated with a combination of resveratrol and phorbol 12-myristate 13-acetate (PMA), a carcinogen known to increase MMP-9 and COX-2 through NF-?B. We found that resveratrol efficiently reversed the PMA-induced MMP-9 secretion and COX-2 expression. Gene silencing of Sirt1, a critical modulator of angiogenesis and putative target of resveratrol, did not lead to significant reversal of MMP-9 and COX-2 inhibition. Decreased resveratrol inhibitory potential of carcinogen-induced I?B phosphorylation in siSirt1-transfected HBMEC was however observed. Our results suggest that resveratrol may prevent BBB disruption during neuroinflammation by inhibiting MMP-9 and COX-2 and act as a pharmacological NF-?B signal transduction inhibitor independent of Sirt1.

Annabi, Borhane; Lord-Dufour, Simon; Vezina, Amelie; Beliveau, Richard

2012-01-01

224

Resveratrol Targeting of Carcinogen-Induced Brain Endothelial Cell Inflammation Biomarkers MMP-9 and COX-2 is Sirt1-Independent.  

PubMed

The occurrence of a functional relationship between the release of metalloproteinases (MMPs) and the expression of cyclooxygenase (COX)-2, two inducible pro-inflammatory biomarkers with important pro-angiogenic effects, has recently been inferred. While brain endothelial cells play an essential role as structural and functional components of the blood-brain barrier (BBB), increased BBB breakdown is thought to be linked to neuroinflammation. Chemopreventive mechanisms targeting both MMPs and COX-2 however remain poorly investigated. In this study, we evaluated the pharmacological targeting of Sirt1 by the diet-derived and antiinflammatory polyphenol resveratrol. Total RNA, cell lysates, and conditioned culture media from human brain microvascular endothelial cells (HBMEC) were analyzed using qRT-PCR, immunoblotting, and zymography respectively. Tissue scan microarray analysis of grade I-IV brain tumours cDNA revealed increased gene expression of Sirt-1 from grade I-III but surprisingly not in grade IV brain tumours. HBMEC were treated with a combination of resveratrol and phorbol 12-myristate 13-acetate (PMA), a carcinogen known to increase MMP-9 and COX-2 through NF-?B. We found that resveratrol efficiently reversed the PMA-induced MMP-9 secretion and COX-2 expression. Gene silencing of Sirt1, a critical modulator of angiogenesis and putative target of resveratrol, did not lead to significant reversal of MMP-9 and COX-2 inhibition. Decreased resveratrol inhibitory potential of carcinogen-induced I?B phosphorylation in siSirt1-transfected HBMEC was however observed. Our results suggest that resveratrol may prevent BBB disruption during neuroinflammation by inhibiting MMP-9 and COX-2 and act as a pharmacological NF-?B signal transduction inhibitor independent of Sirt1. PMID:22523472

Annabi, Borhane; Lord-Dufour, Simon; Vézina, Amélie; Béliveau, Richard

2012-01-01

225

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

PubMed

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

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

2014-06-01

226

Expression of COX-2, NF-?B-p65, NF-?B-p50 and IKK? in malignant and adjacent normal human colorectal tissue  

PubMed Central

BACKGROUND: Cyclooxygenase-2 (COX-2) is selectively over-expressed in colorectal tumours. The mechanism of COX-2 induction in these tumours is not fully understood, although evidence suggests a possible link between nuclear factor (NF)-?B and COX-2. We hypothesised an association between COX-2 expression and NF-?B-p65, NF-?B-p50 and I?B-kinase-? (IKK?) in both epithelial and stromal cells in human colorectal cancer. Methods: Using immunohistochemistry, we measured COX-2, NF-?B-p65, NF-?B-p65 nuclear localisation sequence (NLS), NF-?B-p50, NF-?B-p50 NLS and IKK? protein expression in matched colorectal biopsy samples comprising both non-tumour and adjacent tumour tissue from 32 patients with colorectal cancer. Results: We have shown that stromal cells of malignant and surrounding normal colorectal tissue express COX-2. In all cell types of malignant tissue, and in vascular endothelial cells (VECs) of neighbouring normal tissue, COX-2 expression was strongly associated with NF-?B-p65 expression (Pearson's correlation, P=0.019 for macrophages, P=0.001 for VECs, P=0.002 for fibroblasts (malignant tissue), and P=0.011 for VECs (non-malignant tissue)) but not NF-?B-p50 or IKK?. Conclusions: These data suggest that in these cells COX-2 induction may be mediated through activation of the canonical NF-?B pathway. Finally, the lack of association between COX-2, NF-?B-p65 or IKK? in stromal cells with the clinical severity of colorectal cancer as determined by Duke's stage, suggests that COX-2, NF-?B-p65 and IKK? expression are possibly early post-initiation events, which could be involved in tumour progression.

Charalambous, M P; Lightfoot, T; Speirs, V; Horgan, K; Gooderham, N J

2009-01-01

227

Influence of COX-2 and OXTR polymorphisms on treatment outcome in treatment resistant depression.  

PubMed

Inflammatory pathways play a crucial role in the pathomechanisms of antidepressant efficacy. The aim of this study was to investigate whether a set of single nucleotide polymorphisms (SNPs) within cyclooxygenase-2 (COX-2, rs5275 and rs20417) and oxytocin receptor (OXTR, rs53576 and rs2254298) genes was associated with antidepressant treatment resistance, response or remission. Three hundred seventy-two patients were recruited in the context of a multicenter resistant depression study. They were genotyped for COX-2 and OXTR SNPs. Treatment resistance (according to two different definitions), response and remission were recorded. We did not observe any association between the genotypes or alleles of the selected SNPs within COX-2 and OXTR genes and treatment resistance, response and remission in the whole sample. Our results are consistent with those of some studies but not with those of other ones. Indeed, several factors could be involved in the discrepancy observed across studies. They include sample size, environmental factors, differences in ethnicity, different study designs, and different definitions of treatment resistance. PMID:22487732

Mendlewicz, Julien; Crisafulli, Concetta; Calati, Raffaella; Kocabas, Neslihan Aygun; Massat, Isabelle; Linotte, Sylvie; Kasper, Siegfried; Fink, Martin; Sidoti, Antonina; Scantamburlo, Gabrielle; Ansseau, Marc; Antonijevic, Irina; Forray, Carlos; Snyder, Lenore; Bollen, Joseph; Montgomery, Stuart; Zohar, Joseph; Souery, Daniel; Serretti, Alessandro

2012-05-10

228

Evaluation of cyclooxygenase-2 inhibitors using pulsed ultrafiltration mass spectrometry.  

PubMed

Since selective inhibition of the inducible form of cyclooxygenase (COX-2) might retain all the benefits of classical nonsteroidal antiinflammatory agents while avoiding the major side effects associated with inhibition of the constitutive isoform COX-1, COX-2 has become an important target for the discovery and development of new antiinflammatory drugs. To aid in the discovery and characterization of such selective inhibitors, we have applied a mass spectrometry-based screening technique, pulsed ultrafiltration mass spectrometry, using COX-2 as the target. In a blind study, 18 samples enriched with one or more inhibitors of COX-2 were evaluated. The matrixes for the test samples consisted of DMSO, r DMSO solutions of a plant extract, or a bacterial fermentation broth extract. The composition of the samples was unknown during the assays, as were the concentrations of the COX-2 inhibitors. A soluble recombinant form of human COX-2 was incubated with each sample, and then an aliquot of each mixture was injected into the stirred ultrafiltration chamber fitted with a 30000 MW cutoff ultrafiltration membrane. After the unbound and weakly bound compounds were washed away, the ligand-receptor complexes were disrupted using an acidified 10% methanol solution. The released ligands were trapped on a C18 cartridge and then identified using liquid chromatography-negative ion electrospray mass spectrometry with the trapping cartridge as the HPLC column. Neither the plant matrix nor the fermentation broth extract were found to interfere with the assay. Two or three ligands for COX-2 were identified in each sample, which included polar and nonpolar compounds and inhibitors with IC50 values ranging from 100 microM to 10 nM. PMID:10959973

Nikolic, D; Habibi-Goudarzi, S; Corley, D G; Gafner, S; Pezzuto, J M; van Breemen, R B

2000-08-15

229

Identification of MAGI1 as a tumor-suppressor protein induced by cyclooxygenase-2 inhibitors in colorectal cancer cells  

Microsoft Academic Search

Cyclooxyganase-2 (COX-2), a rate-limiting enzyme in the prostaglandin synthesis pathway, is overexpressed in many cancers and contributes to cancer progression through tumor cell-autonomous and paracrine effects. Regular use of non-steroidal anti-inflammatory drugs or selective COX-2 inhibitors (COXIBs) reduces the risk of cancer development and progression, in particular of the colon. The COXIB celecoxib is approved for adjunct therapy in patients

J Zaric; J-M Joseph; S Tercier; T Sengstag; L Ponsonnet; M Delorenzi; C Rüegg

2012-01-01

230

Modulation of Ionizing Radiation-Induced G{sub 2} Arrest by Cyclooxygenase-2 and its Inhibitor Celecoxib  

SciTech Connect

Purpose: Prolongation or attenuation of ionizing radiation (IR)-induced G{sub 2}-M arrest in cyclooxygenase-2 (COX-2) overexpressing or celecoxib-treated cells, respectively, has been previously observed. To better understand the molecular mechanisms involved, we investigated the molecules involved in G{sub 2} checkpoint pathways after treatment with IR {+-} celecoxib. Methods and Materials: Various molecules in the G{sub 2} checkpoint pathways were investigated in HCT-116-Mock and -COX-2 cells. Western blot, reverse transcriptase polymerase chain reaction, confocal microscopy, and fluorescence activated cell sorter (FACS) analyses were performed to investigate whether expression and activity of the ataxia telangiectasia and rad3-related (ATR) could be modulated by COX-2 and its selective inhibitors. Results: COX-2 overexpression increased expression and activity of ATR after IR exposure. Celecoxib downregulated ATR in all tested cell lines independent of COX-2 expression, but downregulation was greater in COX-2 overexpressing cells after cells were irradiated. Celecoxib pretreatment before radiation caused strongly inhibited G{sub 2} arrest. Conclusions: COX-2 appears to prolong IR-induced G{sub 2} arrest by upregulating ATR. Celecoxib downregulated ATR preferentially in irradiated COX-2 overexpressing cells. Celecoxib may radiosensitize cancer cells by inhibiting G{sub 2} arrest through ATR downregulation.

Jun, Hyun Jung; Kim, Young Mee; Park, Soo Yeon [Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Park, Ji Sun [Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Massachusetts General Hospital Cancer Center and Department of Medicine, Harvard Medical School, Boston, MA (United States); Lee, Eun Jung; Choi, Shin Ae [Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Pyo, Hongryull [Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of)], E-mail: quasar93@ncc.re.kr

2009-09-01

231

COX-2 inhibition in schizophrenia and major depression.  

PubMed

In schizophrenia and depression, opposite patterns of type-1 - type-2 immune response seem to be associated with differences in the activation of the enzyme indoleamine 2,3-dioxygenase (IDO) and in the tryptophan - kynurenine metabolism resulting in increased production of kynurenic acid in schizophrenia and decreased production of kynurenic acid in depression. These differences are associated with an imbalance in the glutamatergic neurotransmission, which may contribute to an overweight of N-methyl-D-aspartate (NMDA) agonism in depression and of NMDA antagonism in schizophrenia. The differential activation of microglia cells and astrocytes may be an additional mechanism contributing to this imbalance. The immunological imbalance results both in schizophrenia and in depression in an increased Prostaglandin E(2) (PGE(2)) production and probably also in an increased Cyclo-oxygenase-2 (COX-2) expression. Although there is strong evidence for the view, that the interactions of the immune system, IDO, the serotonergic system, and the glutamatergic neurotransmission play a key role in schizophrenia and in depression, several gaps, e.g. the roles of genetics, disease course, sex, different psychopathological states, etc. have to be bridged by intense further research. There are already hints that anti-inflammatory therapy may have beneficial effects in schizophrenia and major depression. COX-2 inhibititors have been tested in animal models of depression and in preliminary clinical trials, the latter showing favourable effects compared to placebo, both, in schizophrenia and in major depression. The effects of COX-2 inhibition in the central nervous system (CNS) as well as the different components of the inflammatory system, the kynurenine-metabolism and the glutamatergic neurotransmission, however, still need careful further validation including clinical studies with sufficient sample size. PMID:18537668

Müller, Norbert; Schwarz, Markus J

2008-01-01

232

Selecting a Selective Serotonin Reuptake Inhibitor: Clinically Important Distinguishing Features  

PubMed Central

Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed to treat depression. Although these drugs presumably have the same mechanism of action, they vary in several clinically important ways, including how long they remain in the body and the extent to which they interfere with the metabolism of other medications. This article reviews the pharmacologic differences among SSRIs and how these differences may affect various aspects of treatment, such as dosing, administration, and discontinuation. Understanding the distinct properties of SSRIs may help primary care physicians to design the most appropriate therapeutic plan for individual patients.

Marken, Patricia A.; Munro, J. Stuart

2000-01-01

233

A cross-talk between NFAT and NF-?B pathways is crucial for nickel-induced COX-2 expression in Beas-2B cells.  

PubMed

Cyclooxygenase-2 (COX-2) is a critical enzyme implicated in chronic inflammation-associated cancer development. Our studies have shown that the exposure of Beas-2B cells, a human bronchial epithelial cell line, to lung carcinogenic nickel compounds results in increased COX-2 expression. However, the signaling pathways leading to nickel-induced COX-2 expression are not well understood. In the current study, we found that the exposure of Beas-2B cells to nickel compounds resulted in the activation of both nuclear factor of activated T cell (NFAT) and nuclear factor-?B (NF-?B). The expression of COX-2 induced upon nickel exposure was inhibited by either a NFAT pharmacological inhibitor or the knockdown of NFAT3 by specific siRNA. We further found that the activation of NFAT and NF-?B was dependent on each other. Since our previous studies have shown that NF-?B activation is critical for nickel-induced COX-2 expression in Beas-2B cells exposed to nickel compounds under same experimental condition, we anticipate that there might be a cross-talk between the activation of NFAT and NF-?B for the COX-2 induction due to nickel exposure in Beas-2B cells. Furthermore, we showed that the scavenging of reactive oxygen species (ROS) by introduction of mitochondrial catalase inhibited the activation of both NFAT and NF-?B, and the induction of COX-2 due to nickel exposure. Taken together, our results defining the evidence showing a key role of the cross-talk between NFAT and NF-?B pathways in regulating nickel-induced COX-2 expression, further provide insight into the understanding of the molecular mechanisms linking nickel exposure to its lung carcinogenic effects. PMID:21486220

Cai, Tongjian; Li, Xueyong; Ding, Jin; Luo, Wenjing; Li, Jingxia; Huang, Chuanshu

2011-06-01

234

Inhibition of COX-2 in Colon Cancer Modulates Tumor Growth and MDR-1 Expression to Enhance Tumor Regression in Therapy-Refractory Cancers In Vivo12  

PubMed Central

Higher cyclooxygenase 2 (COX-2) expression is often observed in aggressive colorectal cancers (CRCs). Here, we attempt to examine the association between COX-2 expression in therapy-refractory CRC, how it affects chemosensitivity, and whether, in primary tumors, it is predictive of clinical outcomes. Our results revealed higher COX-2 expression in chemoresistant CRC cells and tumor xenografts. In vitro, the combination of either aspirin or celecoxib with 5-fluorouracil (5-FU) was capable of improving chemosensitivity in chemorefractory CRC cells, but a synergistic effect with 5-FU could only be demonstrated with celecoxib. To examine the potential clinical significance of these observations, in vivo studies were undertaken, which also showed that the greatest tumor regression was achieved in chemoresistant xenografts after chemotherapy in combination with celecoxib, but not aspirin. We also noted that these chemoresistant tumors with higher COX-2 expression had a more aggressive growth rate. Given the dramatic response to a combination of celecoxib + 5-FU, the possibility that celecoxib may modulate chemosensitivity as a result of its ability to inhibit MDR-1 was examined. In addition, assessment of a tissue microarray consisting of 130 cases of CRCs revealed that, in humans, higher COX-2 expression was associated with poorer survival with a 68% increased risk of mortality, indicating that COX-2 expression is a marker of poor clinical outcome. The findings of this study point to a potential benefit of combining COX-2 inhibitors with current regimens to achieve better response in the treatment of therapy-refractory CRC and in using COX-2 expression as a prognostic marker to help identify individuals who would benefit the greatest from closer follow-up and more aggressive therapy.

Rahman, Mahbuba; Selvarajan, Krithika; Hasan, Mohammad R; Chan, Annie P; Jin, Chaoyang; Kim, Jieun; Chan, Simon K; Le, Nhu D; Kim, Young-Bae; Tai, Isabella T

2012-01-01

235

Inhibition of COX-2 in colon cancer modulates tumor growth and MDR-1 expression to enhance tumor regression in therapy-refractory cancers in vivo.  

PubMed

Higher cyclooxygenase 2 (COX-2) expression is often observed in aggressive colorectal cancers (CRCs). Here, we attempt to examine the association between COX-2 expression in therapy-refractory CRC, how it affects chemosensitivity, and whether, in primary tumors, it is predictive of clinical outcomes. Our results revealed higher COX-2 expression in chemoresistant CRC cells and tumor xenografts. In vitro, the combination of either aspirin or celecoxib with 5-fluorouracil (5-FU) was capable of improving chemosensitivity in chemorefractory CRC cells, but a synergistic effect with 5-FU could only be demonstrated with celecoxib. To examine the potential clinical significance of these observations, in vivo studies were undertaken, which also showed that the greatest tumor regression was achieved in chemoresistant xenografts after chemotherapy in combination with celecoxib, but not aspirin. We also noted that these chemoresistant tumors with higher COX-2 expression had a more aggressive growth rate. Given the dramatic response to a combination of celecoxib + 5-FU, the possibility that celecoxib may modulate chemosensitivity as a result of its ability to inhibit MDR-1 was examined. In addition, assessment of a tissue microarray consisting of 130 cases of CRCs revealed that, in humans, higher COX-2 expression was associated with poorer survival with a 68% increased risk of mortality, indicating that COX-2 expression is a marker of poor clinical outcome. The findings of this study point to a potential benefit of combining COX-2 inhibitors with current regimens to achieve better response in the treatment of therapy-refractory CRC and in using COX-2 expression as a prognostic marker to help identify individuals who would benefit the greatest from closer follow-up and more aggressive therapy. PMID:22904679

Rahman, Mahbuba; Selvarajan, Krithika; Hasan, Mohammad R; Chan, Annie P; Jin, Chaoyang; Kim, Jieun; Chan, Simon K; Le, Nhu D; Kim, Young-Bae; Tai, Isabella T

2012-07-01

236

Cyclooxygenase-2 inhibitors and coronary occlusion - exploring dose-response relationships  

PubMed Central

Aims To investigate the relationship between acute coronary syndrome (ACS) and ingested doses of selective cyclooxygenase-2 (COX-2) inhibitors and other nonsteroidal anti-inflammatory drugs (NSAIDs). Methods Case–control study, commenced August 2003. Cases were patients admitted to hospital with ACS (myocardial infarction/unstable angina). Controls were hospital patients admitted for reasons other than acute vascular ischaemia or conditions that are believed to be complications of treatment with COX-2 inhibitors or NSAIDs. Structured interviews were undertaken within 7 days of admission, collecting information on cardiovascular events and risk factors and all ingested drugs, including the doses of COX-2 inhibitors and NSAID consumed in the previous week and month. Results An interim analysis of the data was conducted in late 2004 to inform a review of the COX-2 inhibitors by the Australian drug regulatory agency. Between August 2003 and October 2004, we recruited 328 ACS cases and 478 controls. With non-use of COX-2 inhibitors or NSAIDs as the reference the adjusted odds ratios (OR) for ACS were: celecoxib 1.11 (95% confidence interval 0.59, 2.11), rofecoxib 0.63 (0.31, 1.28) and other NSAIDs 0.67 (0.41, 1.09). Among control subjects, median daily ingested doses of celecoxib and rofecoxib were 200 mg and 13.4 mg, respectively. Using these to stratify risk, adjusted ORs for ACS were: ‘low’ dose (< median) 0.44 (0.19, 1.03); ‘high’ dose (? median) 1.22 (0.67, 2.21). A test for interaction across doses was statistically significant, OR 2.8 (1.0, 7.7), suggesting that at low doses, COX-2 inhibitors may be protective, becoming risk-inducing only at higher doses. Conclusion The possibility that the gradient of cardiovascular risk with COX-2 inhibitors runs from protective to risk-inducing has biological plausibility and merits further investigation.

McGettigan, Patricia; Han, Pearline; Henry, David

2006-01-01

237

The relationship between mucosal cyclooxygenase-2 (COX2) expression and experimental radiation-induced mucositis  

Microsoft Academic Search

Although cycloooxygenase-2 (COX-2) is upregulated by factors associated with oral mucositis, its role in the pathogenesis of mucositis has not been studied. We investigated the kinetics of mucosal COX-2 expression following radiation exposure, and assessed its relationship to the development of oral mucositis in an established animal model using immunohistochemical endpoints. While little or no COX-2 expression was observed in

S. T. Sonis; K. E. O'Donnell; R. Popat; C. Bragdon; S. Phelan; D. Cocks; J. B. Epstein

2004-01-01

238

Post-Exposure Therapeutic Efficacy of COX-2 Inhibition against Burkholderia pseudomallei  

PubMed Central

Burkholderia pseudomallei is a Gram-negative, facultative intracellular bacillus and the etiologic agent of melioidosis, a severe disease in Southeast Asia and Northern Australia. Like other multidrug-resistant pathogens, the inherent antibiotic resistance of B. pseudomallei impedes treatment and highlights the need for alternative therapeutic strategies that can circumvent antimicrobial resistance mechanisms. In this work, we demonstrate that host prostaglandin E2 (PGE2) production plays a regulatory role in the pathogenesis of B. pseudomallei. PGE2 promotes B. pseudomallei intracellular survival within macrophages and bacterial virulence in a mouse model of pneumonic melioidosis. PGE2-mediated immunosuppression of macrophage bactericidal effector functions is associated with increased arginase 2 (Arg2) expression and decreased nitric oxide (NO) production. Treatment with a commercially-available COX-2 inhibitor suppresses the growth of B. pseudomallei in macrophages and affords significant protection against rapidly lethal pneumonic melioidosis when administered post-exposure to B. pseudomallei-infected mice. COX-2 inhibition may represent a novel immunotherapeutic strategy to control infection with B. pseudomallei and other intracellular pathogens.

Asakrah, Saja; Nieves, Wildaliz; Mahdi, Zaid; Agard, Mallory; Zea, Arnold H.; Roy, Chad J.; Morici, Lisa A.

2013-01-01

239

Feedback amplification of fibrosis through matrix stiffening and COX-2 suppression  

PubMed Central

Tissue stiffening is a hallmark of fibrotic disorders but has traditionally been regarded as an outcome of fibrosis, not a contributing factor to pathogenesis. In this study, we show that fibrosis induced by bleomycin injury in the murine lung locally increases median tissue stiffness sixfold relative to normal lung parenchyma. Across this pathophysiological stiffness range, cultured lung fibroblasts transition from a surprisingly quiescent state to progressive increases in proliferation and matrix synthesis, accompanied by coordinated decreases in matrix proteolytic gene expression. Increasing matrix stiffness strongly suppresses fibroblast expression of COX-2 (cyclooxygenase-2) and synthesis of prostaglandin E2 (PGE2), an autocrine inhibitor of fibrogenesis. Exogenous PGE2 or an agonist of the prostanoid EP2 receptor completely counteracts the proliferative and matrix synthetic effects caused by increased stiffness. Together, these results demonstrate a dominant role for normal tissue compliance, acting in part through autocrine PGE2, in maintaining fibroblast quiescence and reveal a feedback relationship between matrix stiffening, COX-2 suppression, and fibroblast activation that promotes and amplifies progressive fibrosis.

Liu, Fei; Mih, Justin D.; Shea, Barry S.; Kho, Alvin T.; Sharif, Asma S.; Tager, Andrew M.

2010-01-01

240

Combining enzyme specificity and tissue selectivity of cyclooxygenase inhibitors: towards better tolerability?  

Microsoft Academic Search

Inhibitors of cyclooxygenases (COXs) are the most widely used drugs. They reduce discomfort and fever, inhibit peri-operative and inflammatory pain. These effects are largely mediated by inhibition of cyclooxygenase-1 and -2 (COX-1 and COX-2)-enzymes found throughout the body producing prostaglandins, which are important mediators of pain and fever, but also adaptive and protective reactions in many organs. A first step

K. Brune; D. E. Furst

2007-01-01

241

COX-2/EGFR expression and survival among women with adenocarcinoma of the lung  

PubMed Central

Previous studies suggest that cyclooxygenase-2 (COX-2) expression may predict survival among patients with non-small cell lung cancer. COX-2 may interact with epidermal growth factor receptor (EGFR), suggesting that combined COX-2/EGFR expression may provide predictive value. The extent to which their independent or combined expression is associated with prognosis in women with adenocarcinoma of the lung is unknown. In the present study, we examined relationships between COX-2 expression (n?=?238), EGFR expression (n?=?158) and dual COX-2/EGFR expression (n?=?157) and survival among women with adenocarcinoma of the lung. Overall survival was estimated by constructing Cox proportional hazards models adjusting for other significant variables and stratifying by stage at diagnosis and race. Clinical or demographic parameters were not associated with either COX-2 or EGFR expression. Patients with COX-2-positive tumors tended to have poorer prognosis than did patients with COX-2-negative tumors [hazard ratio (HR) 1.67, 95% confidence interval (CI) 1.01–2.78]. African-Americans with COX-2-positive tumors had a statistically non-significant higher risk of death than African-Americans with COX-2-negative tumors (HR 5.58, 95% CI 0.64–48.37). No association between COX-2 expression and survival was observed among Caucasians (HR 1.29, 95% CI 0.72–2.30). EGFR expression was associated with a 44% reduction in the risk of death (HR 0.56, 95% CI 0.32–0.98). COX-2?/EGFR+ tumor expression, but not COX-2+/EGFR+ tumor expression, was associated with survival when compared with other combined expression results. In conclusion, COX-2 and EGFR expression, but not combined COX-2+/EGFR+ expression, independently predict survival of women with adenocarcinoma of the lung.

Van Dyke, Alison L.; Cote, Michele L.; Prysak, Geoffrey M.; Claeys, Gina B.; Wenzlaff, Angie S.; Murphy, Valerie C.; Lonardo, Fulvio; Schwartz, Ann G.

2008-01-01

242

Evaluation of natural products on inhibition of inducible cyclooxygenase (COX2) and nitric oxide synthase (iNOS) in cultured mouse macrophage cells  

Microsoft Academic Search

The inhibitors of prostaglandin biosynthesis and nitric oxide production have been considered as potential anti-inflammatory and cancer chemopreventive agents. In this study, we evaluated approximately 170 methanol extracts of natural products including Korean herbal medicines for the inhibition of prostaglandin E2 production (for COX-2 inhibitors) and nitric oxide formation (for iNOS inhibitors) in lipopolysaccharide (LPS)-induced mouse macrophages RAW264.7 cells. As

Chae Hee Hong; Sun Kyung Hur; O-Jin Oh; Sun Sook Kim; Kyung Ae Nam; Sang Kook Lee

2002-01-01

243

Treatment of selective mutism: focus on selective serotonin reuptake inhibitors.  

PubMed

Abstract Selective mutism is a pediatric psychiatric disorder that occurs when a child consistently fails to speak in specific situations in which speaking is expected, such as at school and social gatherings, but speaks appropriately in other settings. Selective mutism often is diagnosed when a child starts school and does not talk to teachers or peers, but talks to family members at home; the condition is frequently accompanied by anxiety and shyness. Although the underlying etiology of the condition remains unclear, psychotherapy is the preferred initial treatment, with the support of parents and teachers. If the child does not respond to psychotherapy, addition of pharmacologic treatment should be considered, depending on the severity of symptoms and presence of other illnesses. Although data are limited to case reports and trials with small patient populations and short follow-up periods, some patients with selective mutism respond to therapy with selective serotonin reuptake inhibitors (SSRIs). Fluoxetine is the most studied SSRI as treatment for the condition, although further investigation is required to determine the optimal dosage and duration of therapy. PMID:18225967

Kaakeh, Yaman; Stumpf, Janice L

2008-02-01

244

Celecoxib, a cyclooxygenase-2 inhibitor, induces apoptosis in human osteosarcoma cell line MG63 via down-regulation of PI3K\\/Akt  

Microsoft Academic Search

Cyclooxygenase-2 (COX-2), involved in the inhibition of apoptosis and, the potentiation of cell growth, is frequently overexpressed in human malignancies including osteosarcoma (OS). We have attempted to identify the anti-proliferation of celecoxib, a selective COX-2 inhibitor, and the combination of celecoxib and cisplatin in MG-63 cells, and to explore the potential molecular mechanisms involved. MG-63 cells were treated with the

Bing Liu; Zhong-li Shi; Jie Feng; Hui-min Tao

2008-01-01

245

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

SciTech Connect

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 ?M 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.

Pham, Hung [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States) [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States); Department of Medicine, Veterans Affair Greater Los Angeles Healthcare System, Los Angeles, CA 90073 (United States); Ekaterina Rodriguez, C.; Donald, Graham W.; Hertzer, Kathleen M.; Jung, Xiaoman S.; Chang, Hui-Hua; Moro, Aune; Reber, Howard A.; Hines, O. Joe [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States)] [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States); Eibl, Guido, E-mail: geibl@mednet.ucla.edu [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States)] [Department of Surgery, UCLA Center of Excellence in Pancreatic Diseases, UCLA David Geffen School of Medicine, University of California – Los Angeles, Los Angeles, CA 90095 (United States)

2013-09-13

246

Endothelium-mediated control of vascular tone: COX-1 and COX-2 products  

PubMed Central

Endothelium-dependent contractions contribute to endothelial dysfunction in various animal models of aging, diabetes and cardiovascular diseases. In the spontaneously hypertensive rat, the archetypal model for endothelium-dependent contractions, the production of the endothelium-derived contractile factors (EDCF) involves an increase in endothelial intracellular calcium concentration, the production of reactive oxygen species, the predominant activation of cyclooxygenase-1 (COX-1) and to a lesser extent that of COX-2, the diffusion of EDCF towards the smooth muscle cells and the subsequent stimulation of their thromboxane A2-endoperoxide TP receptors. Endothelium-dependent contractions are also observed in various models of hypertension, aging and diabetes. They generally also involve the generation of COX-1- and/or COX-2-derived products and the activation of smooth muscle TP receptors. Depending on the model, thromboxane A2, PGH2, PGF2?, PGE2 and paradoxically PGI2 can all act as EDCFs. In human, the production of COX-derived EDCF is a characteristic of the aging and diseased blood vessels, with essential hypertension causing an earlier onset and an acceleration of this endothelial dysfunction. As it has been observed in animal models, COX-1, COX-2 or both isoforms can contribute to these endothelial dysfunctions. Since in most cases, the activation of TP receptors is the common downstream effector, selective antagonists of this receptor should curtail endothelial dysfunction and be of therapeutic interest in the treatment of cardiovascular disorders. LINKED ARTICLES This article is part of a themed issue on Vascular Endothelium in Health and Disease. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.164.issue-3

Feletou, Michel; Huang, Yu; Vanhoutte, Paul M

2011-01-01

247

Effect of Cyclooxygenase and Nitric Oxide Synthase Inhibitors on Streptozotocin-Induced Hyperalgesia in Rats  

Microsoft Academic Search

We examined a possible involvement of cyclooxygenase (COX) and nitric oxide synthase (NOS) products in hyperalgesia occurring during streptozotocin (STZ)-induced diabetes. Indomethacin and celecoxib were used as relatively selective inhibitors of COX-1 and COX-2, respectively. NOS inhibitors included: non-specific inhibitor NG-nitro-L-arginine and L-N6-(1-iminoethyl)lysine preferentially acting on inducible NOS (iNOS) as well as 7-nitroindazole relatively specific inhibitor neuronal NOS (nNOS). The

Magdalena Bujalska; Jan Tatarkiewicz; Anna de Cordé

2008-01-01

248

The pre-emptive analgesic effect of a cyclooxygenase-2 inhibitor in a rat model of acute postoperative pain.  

PubMed

We examined the pre-emptive analgesic effect of a cyclooxygenase (COX)-2 inhibitor in a rat surgical pain model and characterised the changes in cutaneous COX-2 around a surgical site. Thermal hyperalgesia and mechanical allodynia were tested in the rats for three days after incision and skin tissues were collected for analysis of COX-2. There was decreased expression of cutaneous COX-2 one day after surgical incision. Pre-incision injection of the COX-2 inhibitor significantly inhibited expression of COX-2 and also reduced thermal hyperalgesia (but not mechanical allodynia) compared with the post-incision COX-2-inhibitor injection group, one day after incision. PMID:22823006

Chen, J J; Hung, K C; Lu, K; Yu, S W; Chang, C C; Liu, C C; Spielberger, J; Ku, P Y; Tan, P H

2012-11-01

249

Nilotinib: a Novel, Selective Tyrosine Kinase Inhibitor  

PubMed Central

The development of tyrosine kinase inhibitors (TKIs) for the treatment of chronic myelogenous leukemia (CML) was based on the discovery that CML stem and progenitor cells overexpress the abnormal fusion protein kinase BCR-ABL. The prototype TKI, imatinib, selectively inhibits BCR-ABL, as well as several other kinases, including DDR, KIT, PDGFR, and CSF-1R. Although the management of CML improved dramatically with the introduction of imatinib, not all patients benefit from treatment because of resistance or intolerance. Consequently, research efforts have focused on developing more potent TKIs with the ability to circumvent imatinib resistance. Nilotinib, a second-generation oral TKI, was rationally designed based on the crystal structure of imatinib to be highly active against a wide range of imatinib-resistant BCR-ABL mutants and is approved for the treatment of newly diagnosed or imatinib-resistant or -intolerant CML, and has shown superiority over imatinib in first-line in newly diagnosed CML. Furthermore, the activity of nilotinib against KIT and PDGFR? has led to its evaluation in advanced gastrointestinal stromal tumors (GIST). The purpose of this review is to describe the development of nilotinib, providing a structural explanation for the differential activity of nilotinib and imatinib in GIST. Activity of nilotinib against KIT and PDGFR and emerging evidence of differences in cellular uptake between nilotinib and imatinib are discussed.

Blay, Jean-Yves; von Mehren, Margaret

2014-01-01

250

Butein downregulates phorbol 12-myristate 13-acetate-induced COX2 transcriptional activity in cancerous and non-cancerous breast cells  

Microsoft Academic Search

Butein is a flavonoid isolated from the bark of Rhus verniciflua Stokes and the flowers of Butea monosperma, and is known to be a potential therapeutic drug for treating inflammation and cancer. Cyclooxygenase (COX) converts arachidonic acid to prostanoids, and increased expression of its isoform COX-2 has been observed in breast cancer tissues. It has been suggested that COX inhibitors

Grace Tak Yi Lau; Hui Huang; Shu-mei Lin; Lai K. Leung

2010-01-01

251

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

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. PMID:20676755

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

252

TNF-? and LPA promote synergistic expression of COX-2 in human colonic myofibroblasts: role of LPA-mediated transactivation of upregulated EGFR  

PubMed Central

Background Enhanced EGF receptor (EGFR) signaling is a hallmark of many human cancers, though the role of enhanced EGFR signaling within the surrounding tumor stroma has not been well studied. The myofibroblast is an important stromal cell that demonstrates enhanced EGFR expression in the setting of inflammation, though the functional relevance is not known. We recently reported that TNF-? and the G protein-coupled receptor (GPCR) agonist lysophosphatidic acid (LPA) lead to synergistic cyclo-oxygenase-2 (COX-2) expression, an enzyme strongly associated with the development of colitis-associated cancer. Here, we investigate whether EGFR signaling plays a role in the synergistic COX-2 expression induced by LPA and TNF-?. Methods 18Co cells, a model of human colonic myofibroblasts, were grown to confluence on 35?×?10mm cell culture dishes and were used from passages 10–14. 18Co cells were treated with TNF-? (8.3 ng/ml) and LPA (10 ?M). EGFR and COX-2 protein expression, Y1068 phosphorylation, and p42/44 MAPK phosphorylation were assessed by Western Blot, in the presence and absence of various inhibitors. Results Exposure of 18Co cells to either TNF-? or LPA alone had no effect on EGFR autophosphorylation at Y1068. However, chronic exposure to TNF-? led to upregulation of EGFR in association with sustained LPA-mediated EGFR phosphorylation at Y1068. TNF-? and LPA also led to sustained p42/44 MAPK phosphorylation and synergistic COX-2 expression, effects that were partially inhibited by the EGFR tyrosine kinase inhibitor AG1478. p42/44 MAPK phosphorylation and COX-2 expression were inhibited to the same degree by the MMP inhibitors GM6001 and BB-94, suggesting that LPA-mediated EGFR transactivation involved MMP-mediated release of EGFR ligands from the cell surface. The Src inhibitor SU6556 inhibited TNF-?/LPA-mediated EGFR phosphorylation at Y1068, p42/44 MAPK phosphorylation, and COX-2 expression in a dose-dependent fashion, suggesting an upstream role of Src in the transactivation of EGFR. Conclusion Synergistic COX-2 expression induced by TNF-? and LPA involves Src/MMP-mediated transactivation of EGFR and downstream p42/44 MAPK activation in human colonic myofibroblasts. Enhanced EGFR expression induced by TNF-? promotes GPCR-mediated EGFR transactivation in colonic myofibroblasts, providing an important mechanism for stromal COX-2 over-expression that may predispose to the development of colitis-associated cancer.

2013-01-01

253

Mechanisms of adiponectin-mediated COX-2 induction and protection against iron injury in mouse hepatocytes.  

PubMed

Adiponectin (APN)-mediated cyclooxygenase (COX)-2 induction is known to have various protective effects on cardiovascular diseases. However, the molecular mechanisms of APN-mediated COX-2 induction and its protection against iron-mediated injury in hepatocytes are still unclear. Herein, we show that AMP-mediated peroxisome proliferator-activated receptor (PPAR)alpha activation was attributable to COX-2 induction by APN, which was further confirmed by identifying novel functional PPAR responsive elements (PPREs) in the mouse COX-2 promoter region. Prostaglandin (PG)I2 and PGE2, metabolites of COX-2, time-dependently increased in hepatocytes treated with APN. Interestingly, beraprost and misoprostol, respective agonists for PGI2 and PGE2, mimicked the protective effects of APN in iron-mediated inflammation in hepatocytes. The iron dextran-activated nuclear factor (NF)-kappaB pathway was correlated with the increased production of inflammatory cytokines including tumor necrosis factor-alpha, intercellular adhesion molecule-1, and monocyte chemotactic protein-1. This was eliminated by administration of APN, whereas blockage of PPARalpha activation, an upstream regulator of COX-2 induction by APN, and COX-2 activation reversed the anti-inflammatory effect of APN, suggesting the crucial role of COX-2 in this event. Herein, we demonstrate that APN-mediated COX-2 induction through a PPARalpha-dependent mechanism, and COX-2 exerted an anti-inflammatory effect of APN in hepatocytes subjected to iron challenge. PMID:20583136

Lee, Fei-Peng; Jen, Chih-Yu; Chang, Chih-Cheng; Chou, Ying; Lin, Heng; Chou, Chih-Ming; Juan, Shu-Hui

2010-09-01

254

Palmitate induces COX-2 expression via the sphingolipid pathway-mediated activation of NF-?B, p38, and ERK in human dermal fibroblasts.  

PubMed

It has been suggested that free fatty acids (FFA) such as palmitate, which are secreted from enlarged adipocytes in the subcutaneous fat of obese subjects, serve as a link between obesity and altered skin functions. Cyclooxygenease-2 (COX-2) and prostanoids participate in the induction of impaired dermal function. In the current study, we investigated the issue of whether palmitate induces COX-2 expression via the sphingolipid pathway-mediated activation of NF-?B or mitogen-activated protein kinase (MAPK) pathways in human dermal fibroblasts. Palmitate treatment significantly induced COX-2 expression and prostaglandin E2 (PGE2) release in human dermal fibroblasts. In addition, pre-treatment with triacsin C, an inhibitor of acyl-CoA synthetase in de novo ceramide synthesis, was found to reduce palmitate-induced COX-2 expression and PGE2 release in human dermal fibroblast. The findings also show that palmitate-induced COX-2 expression and PGE2 release are mediated by the NF-?B, p38, and extracellular signal-regulated kinase (ERK) MAPK pathways. These findings point to a new mechanism for explaining the link between increased FFAs in obesity and impaired dermal function. PMID:24337700

Oh, Eunhye; Yun, Mihee; Kim, Seong Keun; Seo, Gimoon; Bae, Joon Sung; Joo, Kwon; Chae, Gue Tae; Lee, Seong-Beom

2014-05-01

255

The Antioxidant Effects of Isorhamnetin Contribute to Inhibit COX-2 Expression in Response to Inflammation: A Potential Role of HO-1.  

PubMed

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. PMID:24337631

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

2014-06-01

256

Dual EGFR and COX-2 inhibition as a novel approach to targeting head and neck squamous cell carcinoma.  

PubMed

Epidermal growth factor inhibition (EGFR) is emerging as an important treatment modality in several epithelial malignancies, including head and neck squamous cell carcinoma (HNSCC). Despite some notable successes, less than 20% of patients respond to EGFR inhibition due to intrinsic and acquired resistance. Since EGFR inhibition is already used for lung, colorectal, breast and pancreas cancers in addition to HNSCC, overcoming treatment resistance would have a major impact on outcome. When the mechanisms of intrinsic resistance are identified, including mutations in the EGFR receptor, alternative therapeutic approaches should be employed. Mechanisms of acquired resistance that may be amenable to pharmacological therapies include dysregulation of EGFR degradation, constitutive activation of overlapping signal transduction pathways, especially cMET/HER3, the PI3K/Akt resistance pathway, angiogenesis and epithelial to mesenchymal transition. COX-2 is another promising target for HNSCC and preclinical data suggest that COX-2 inhibitors can affect most of the described acquired EGFR resistance pathways. Several combined EGFR and COX-2 inhibition trials have been completed and demonstrate promise for HNSCC. Combinatorial strategies of combined inhibition of EGFR and acquired resistance pathways in combination with radiation or chemotherapy are warranted. PMID:20025602

Kao, J; Sikora, A T; Fu, S

2009-12-01

257

Nonsteroidal anti-inflammatory drug-activated gene-1 plays a role in the impairing effects of cyclooxygenase inhibitors on gastric ulcer healing.  

PubMed

Nonsteroidal anti-inflammatory drugs (NSAIDs) can impair gastric ulcer healing. This study investigates the involvement of NSAID-activated gene-1 (NAG-1) in ulcer repair impairment by cyclooxygenase (COX) inhibitors. Gastric ulcers were induced in rats by acetic acid. Four days later, animals received daily intragastric indomethacin (nonselective COX-1/COX-2 inhibitor; 1 mg/kg), 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole (SC-560) (selective COX-1 inhibitor; 2.5 mg/kg), (5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl) phenyl-2(5H)-furanone (DFU) (selective COX-2 inhibitor; 5 mg/kg), celecoxib (selective COX-2 inhibitor; 1 mg/kg), and valdecoxib (selective COX-2 inhibitor; 1 mg/kg), for 1, 3, or 7 days. Ulcerated tissues were processed to assess: 1) COX-1, COX-2, NAG-1, proliferating cell nuclear antigen (PCNA), and activated caspase-3 expression; 2) ulcer area; and 3) prostaglandin E(2) (PGE(2)) levels. COX-1 expression in ulcerated tissues was decreased, whereas COX-2 expression was enhanced. Ulcer healing was delayed by indomethacin, DFU, and SC-560, but not by celecoxib and valdecoxib. Ulcer PGE(2) levels were decreased by SC-560, DFU, celecoxib, valdecoxib, and indomethacin. NAG-1 was overexpressed in ulcerated tissues and further enhanced by indomethacin, DFU, and SC-560, but not by celecoxib or valdecoxib. PCNA expression in ulcerated areas was reduced by indomethacin, but not by the other test drugs. The expression of activated caspase-3 in ulcers was increased and enhanced further by indomethacin, DFU, and SC-560, but not by celecoxib and valdecoxib. These findings indicate that: 1) COX inhibitors exert differential impairing effects on gastric ulcer healing, through mechanisms unrelated to the inhibition of COX isoforms and prostaglandin production; and 2) NAG-1 induction, followed by activation of proapoptotic pathways, can contribute to the impairing effects of COX inhibitors on ulcer healing. PMID:22495067

Colucci, Rocchina; Antonioli, Luca; Bernardini, Nunzia; Ippolito, Chiara; Segnani, Cristina; Awwad, Oriana; Tuccori, Marco; Blandizzi, Corrado; Scarpignato, Carmelo; Fornai, Matteo

2012-07-01

258

Modulation of COX2 expression in peripheral blood cells by increased intake of fruit and vegetables?  

Microsoft Academic Search

Background:Enhanced cyclooxygenase-2 (COX-2) expression is associated with carcinogenesis, ischemia, angiogenesis, inflammation, and neurodegeneration. The preventing effect of aspirin and nonsteroidal anti-inflammatory drugs is partly due to inhibition of the COX-2 enzyme. Fruit and vegetables (FVs) contain numerous compounds that may decrease disease risk by several different mechanisms, for example through the inhibition of COX-2 activity.Objective:We tested the hypothesis that an

K Almendingen; A Brevik; D A Nymoen; H T Hilmarsen; P A Andresen; L F Andersen; M Vatn

2005-01-01

259

Probiotics Regulate the Expression of COX2 in Intestinal Epithelial Cells  

Microsoft Academic Search

Cyclooxygenase-2 (COX) 2 promotes intestinal wound healing but elicits also proinflammatory effects and has been implicated in colorectal carcinogenesis. Thus, a balanced expression of COX-2 is essential for intestinal homeostasis. This study was designed to evaluate the regulation of COX-2 by probiotic organisms and to characterize ligands and receptors involved. Colo320 and SW480 intestinal epithelial cells (IEC) were stimulated with

Jan-Michel Otte; Rudja Mahjurian-Namari; Stephan Brand; Ilka Werner; Wolfgang E. Schmidt; Frank Schmitz

2008-01-01

260

IL20, an anti-angiogenic cytokine that inhibits COX2 expression  

Microsoft Academic Search

COX-2 overexpression and subsequent PGE2 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 PGE2 in human bronchial epithelial and endothelial cells. Flow cytometry analysis suggests that IL-20-dependent inhibition of COX-2\\/PGE2 occurs through the IL-22R1\\/IL-20R2 dimers. In addition, we report that IL-20

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

2005-01-01

261

Synergistic Regulation of COX2 Expression by Bombesin and Transforming Growth Factor-?  

Microsoft Academic Search

Overexpression of cyclooxygenase-2 (COX-2), an inducible enzyme regulating prostaglandin release, is mechanistically linked\\u000a to the development, growth, and spread of gastrointestinal (GI) cancers. GI peptide bombesin (BBS) was reported to stimulate\\u000a COX-2 gene expression. Here we show that TGF-?1 dramatically enhances the BBS-induced expression of COX-2 mRNA and protein,\\u000a and the release of PGE2 in the model rat intestinal epithelial

Yan-Shi Guo; Zihong Chen; Xiao-Dong Wen; Tien C. Ko; Courtney M. Townsend Jr; Mark R. Hellmich

2008-01-01

262

Expression of COX2 in Stomach Cancers and Its Relation to Their Biological Features  

Microsoft Academic Search

Background\\/Aim: Cyclooxygenase-2 (COX-2) is one of the key isoenzymes in the production of prostaglandins, and is believed to be involved in carcinogenesis. This study was conducted to examine the role of COX-2 in the development and biological behavior of stomach cancer. Methods: Expression of COX-2 at the mRNA and protein levels was analyzed using RT-PCR and immunoblotting assay in 50

Shao-Liang Han; Huai-Jing Tang; Ya-Wei Hua; She-Qing Ji; Dong-Xin Lin

2003-01-01

263

Chapter 2: Mechanistic Aspects of COX-2 Expression in Colorectal Neoplasia  

PubMed Central

The cyclooxygenase-2 (COX-2) enzyme catalyzes the rate-limiting step of prostaglandin formation in pathogenic states and a large amount of evidence has demonstrated constitutive COX-2 expression to be a contributing factor promoting colorectal cancer (CRC). Various genetic, epigenetic, and inflammatory pathways have been identified to be involved in the etiology and development of CRC. Alteration in these pathways can influence COX-2 expression at multiple stages of colon carcinogenesis allowing for elevated prostanoid biosynthesis to occur in the tumor microenvironment. In normal cells, COX-2 expression levels are potently regulated at the post-transcriptional level through various RNA sequence elements present within the mRNA 3?-untranslated region(3?UTR). A conserved AU-rich element(ARE) functions to target COX-2 mRNA for rapid decay and translational inhibition through association with various RNA-binding proteins to influence the fate of COX-2 mRNA. Specific microRNAs bind regions within the COX-2 3?UTR and control COX-2 expression. In this chapter, we discuss novel insights in the mechanisms of altered posttranscriptional regulation of COX-2 in CRC and how this knowledge may be used to develop novel strategies for cancer prevention and treatment.

Dixon, Dan A.; Blanco, Fernando F.; Bruno, Annalisa; Patrignani, Paola

2012-01-01

264

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

SciTech Connect

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.

Pachkoria, Ketevan [Department of Oncology, Institute of Biomedicine and Surgery, University of Linkoeping, Linkoeping (Sweden); Zhang Hong [Department of Dermatology, Institute of Biomedicine and Surgery, University of Linkoeping, Linkoeping (Sweden); Adell, Gunnar [Department of Oncology, Institute of Biomedicine and Surgery, University of Linkoeping, Linkoeping (Sweden); Jarlsfelt, Ingvar [Department of Pathology and Cytology, Joenkoeping Hospital, Joenkoeping (Sweden); Sun Xiaofeng [Department of Oncology, Institute of Biomedicine and Surgery, University of Linkoeping, Linkoeping (Sweden)]. E-mail: xiao-feng.sun@ibk.liu.se

2005-11-01

265

5-methoxyindole metabolites of L-tryptophan: control of COX-2 expression, inflammation and tumorigenesis  

PubMed Central

Cyclooxygenase-2(COX-2) overexpression promotes inflammation and tumorigenesis. COX-2 expression in response to diverse stimuli is tightly controlled to avoid persistent overexpression. 5-methoxyindole metabolites of L-tryptophan represent a new class of compounds that control COX-2 expression at the transcriptional level. Two of the metabolites, the newly discovered 5-methoxytryptophan (5-MTP, also known as cytoguardin) and N-acetyl 5-methoxytryptamine (melatonin) are the focus of this review. 5-MTP is produced by mesenchymal cells such as fibroblasts via 5-hydroxytryptophan (5-HTP). It inhibits COX-2 transcriptional activation induced by diverse proinflammatory and mitogenic factors. Cancer cells are deficient in cytoguardin production which contributes to COX-2 overexpression. Fibroblast-generated 5-MTP is capable of restoring the control of COX-2 overexpression in cancer cells. 5-MTP blocks cancer cell migration and invasion in vitro and inhibits tumor growth and cancer metastasis in a xenograft model. Melatonin possesses similar COX-2 suppressing and anti-cancer properties albeit at supra-pharmacological concentrations. By contrast, 5-hydroxyindole metabolites of L-tryptophan such as 5-hydroxytryptamine (serotonin), 5-hydroxytryptophol and other serotonin catabolites do not control COX-2 expression. 5-hydroxytryptophan inhibits COX-2 expression through conversion to 5-MTP. The physiological relevance of 5-MTP as an endogenous regulator of inflammation and cancer metastasis remains to be investigated. On the other hand, 5-methoxyindole metabolites of tryptophan are valuable lead compounds for development of new anti-inflammatory drugs and cancer chemoprevention.

2014-01-01

266

Cyclic tensile force up-regulates BMP-2 expression through MAP kinase and COX-2/PGE2 signaling pathways in human periodontal ligament cells.  

PubMed

Periodontal ligament cells play important roles in the homeostasis of periodontal tissue by mechanical stress derived from mastication, such as tension, compression, fluid shear, and hydrostatic force. In the present study, we showed that cyclic tensile force increased the gene expression level of bone morphogenetic protein (BMP)-2, a crucial regulator of mineralization, in human periodontal ligament cells using real-time PCR. Signaling inhibitors, PD98059/U0126 (extracellular signal-regulated kinase (ERK) inhibitors) and SB203580/SB202190 (p38 inhibitors), revealed that tensile force-mediated BMP-2 expression was dependent on activation of the ERK1/2 and p38 mitogen-activated protein (MAP) kinase pathways. Cyclic tensile force also induced cyclooxygenase-2 (COX-2) gene expression in a manner dependent on ERK1/2 and p38 MAP kinase pathways, and induced prostaglandin E2 (PGE2) biosynthesis. NS-398, a COX-2 inhibitor, significantly reduced tensile force-mediated BMP-2 expression, indicating that PGE2 synthesized by COX-2 may be involved in the BMP-2 induction. The inhibitory effect of NS-398 was completely restored by the addition of exogenous PGE2. However, stimulation with PGE2 alone in the absence of tensile force had no effect on the BMP-2 induction, indicating that some critical molecule(s) other than COX-2/PGE2 may be required for cyclic tensile force-mediated BMP-2 induction. Collectively, the results indicate that cyclic tensile force activates ERK1/2 and p38 MAP kinase signaling pathways, and induces COX-2 expression, which is responsible for the sequential PGE2 biosynthesis and release, and furthermore, mediates the increase in BMP-2 expression at the transcriptional level. PMID:24561081

Suzuki, Risako; Nemoto, Eiji; Shimauchi, Hidetoshi

2014-04-15

267

The pharmacogenetics of the selective serotonin reuptake inhibitors  

Microsoft Academic Search

Citalopram, fluoxetine, fluvoxamine, paroxetine and sertraline are selective serotonin reuptake inhibitors (SSRIs), which are thought to act as antidepressants through their ability to inhibit presynaptic serotonin reuptake in the brain. The elimination of the SSRIs proceeds predominantly via oxidation catalyzed by cytochrome P450 in the liver. Paroxetine and fluoxetine are potent inhibitors of cytochrome P4502D6 and hence may cause serious

K. Brøsen

1993-01-01

268

Sulforaphane suppresses lipopolysaccharide-induced cyclooxygenase-2 (COX2) expression through the modulation of multiple targets in COX2 gene promoter  

Microsoft Academic Search

Sulforaphane is a natural, biologically active compound extracted from cruciferous vegetables such as broccoli and cabbage. It possesses potent anti-inflammation and anti-cancer properties. The mechanism by which sulforaphane suppresses COX-2 expression remains poorly understood. In the present report, we investigated the effect of sulforaphane on the expression of COX-2 in lipopolysaccharide (LPS)-activated Raw 264.7 cells. Sulforaphane significantly suppressed the LPS-induced

Kyung Jin Woo; Taeg Kyu Kwon

2007-01-01

269

Discovery of cyclooxygenase inhibitors from medicinal plants used to treat inflammation  

PubMed Central

Eleven authenticated botanicals used in the traditional Chinese medicine Huo-Luo-Xiao-Ling Dan were screened for ligands to cyclooxygenase (COX) using pulsed ultrafiltration liquid chromatography-mass spectrometry, and a mass spectrometry-based enzyme assay was used to determine the concentration of each of 17 ligands that inhibited COX-1 or COX-2 by 50% (IC50). Acetyl-11-keto-?-boswellic -boswellic acid, acid, acetyl-?-boswellic acid, acetyl-?-boswellic acid, and betulinic acid were COX-1 selective inhibitors with IC50 values of approximately 10 ?M. Senkyunolide O and cryptotanshinone were COX-2 selective inhibitors with IC50 values of 5 and 22 ?M, respectively. Roburic acid and phenethyl-trans-ferulate inhibited COX-1 and COX-2 equally. COX inhibition and the IC50 values of most of these natural product ligands have not been reported previously.

Cao, Hongmei; Yu, Rui; Choi, Yongsoo; Ma, Zhong-Ze; Zhang, Hongjie; Xiang, Wei; Lee, David Yue-Wei; Berman, Brian M.; Moudgil, Kamal D; Fong, Harry H.S.; van Breemen, Richard B.

2010-01-01

270

COX-2 but Not mPGES-1 Contributes to Renal PGE2 Induction and Diabetic Proteinuria in Mice with Type-1 Diabetes  

PubMed Central

Prostaglandin E2 (PGE2) has been implicated to play a pathogenic role in diabetic nephropathy (DN) but its source remains unlcear. To elucidate whether mPGES-1, the best characterized PGE2 synthase, was involved in the development of DN, we examined the renal phenotype of mPGES-1 KO mice subjected to STZ-induced type-1 diabetes. After STZ treatment, mPGES-1 WT and KO mice presented the similar onset of diabetes as shown by similar elevation of blood glucose. Meanwhile, both genotypes of mice exhibited similar increases of urinary and renal PGE2 production. In parallel with this comparable diabetic status, the kidney injury indices including the urinary albumin excretion, kidney weight and the kidney histology (PAS staining) did not show any difference between the two genotypes. By Western-blotting and quantitative qRT-PCR, mPGES-1, mPGES-2, cPGES and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) remain unaltered following six weeks of diabetes. Finally, a selective COX-2 inhibitor celecoxib (50 mg/kg/day) was applied to the STZ-treated KO mice, which resulted in significant reduction of urinary albumin excretion (KO/STZ: 141.5±38.4 vs. KO/STZ + Celebrex: 48.7±20.8 ug/24 h, p<0.05) and the blockade of renal PGE2 induction (kidney: KO/STZ: 588.7±89.2 vs. KO/STZ + Celebrex: 340.8±58.7 ug/24 h, p<0.05; urine: KO/STZ 1667.6±421.4 vs. KO/STZ + Celebrex 813.6±199.9 pg/24 h, p<0.05), without affecting the blood glucose levels and urine volume. Taken together, our data suggests that an as yet unidentified prostaglanind E synthase but not mPGES-1 may couple with COX-2 to mediate increased renal PGE2 sythsesis in DN.

Liu, Shanshan; Liu, Ying; Yang, Tianxin

2014-01-01

271

Development of a highly selective c-Src kinase inhibitor  

PubMed Central

Generating highly selective probes to interrogate protein kinase function in biological studies remains a challenge and new strategies are required. Herein, we describe the development of the first highly selective and cell permeable inhibitor of c-Src, a key signaling kinase in cancer. Our strategy involves extension of traditional inhibitor design by appending functionality proposed to interact with the phosphate-binding loop of c-Src. Using our selective inhibitor, we demonstrate that selective inhibition is significantly more efficacious than pan-kinase inhibition in slowing the growth of cancer cells. We also show that inhibition of c-Abl kinase, an off-target of most c-Src inhibitors, promotes oncogenic cell growth.

Brandvold, Kristoffer R.; Steffey, Michael E.; Fox, Christel C.; Soellner, Matthew B.

2012-01-01

272

Screen for Selective Inhibitors or Activators of SMAD Protein Function.  

National Technical Information Service (NTIS)

A method of screening for selective inhibitors or activators Smad protein function is disclosed. In one embodiment, the invention comprises the steps of (a) obtaining a phosphorylated Smad protein or protein complex, (b) allowing the phosphorylated Smad p...

A. R. Comer F. M. Hoffman

2002-01-01

273

Potent and selective inhibitors of the proteasome: Dipeptidyl boronic acids  

Microsoft Academic Search

Potent and selective dipeptidyl boronic acid proteasome inhibitors are described. As compared to peptidyl aldehyde compounds, boronic acids in this series display dramatically enhanced potency. Compounds such as 15 are promising new therapeutics for treatment of cancer and inflammatory diseases.

Julian Adams; Mark Behnke; Shaowu Chen; Amy A. Cruickshank; Lawrence R. Dick; Louis Grenier; Janice M. Klunder; Yu-Ting Ma; Louis Plamondon; Ross L. Stein

1998-01-01

274

Reversible Suppression of Cyclooxygenase 2 (COX-2) Expression In Vivo by Inducible RNA Interference  

PubMed Central

Prostaglandin-endoperoxide synthase 2 (PTGS2), also known as cyclooxygenase 2 (COX-2), plays a critical role in many normal physiological functions and modulates a variety of pathological conditions. The ability to turn endogenous COX-2 on and off in a reversible fashion, at specific times and in specific cell types, would be a powerful tool in determining its role in many contexts. To achieve this goal, we took advantage of a recently developed RNA interference system in mice. An shRNA targeting the Cox2 mRNA 3?untranslated region was inserted into a microRNA expression cassette, under the control of a tetracycline response element (TRE) promoter. Transgenic mice containing the COX-2-shRNA were crossed with mice encoding a CAG promoter-driven reverse tetracycline transactivator, which activates the TRE promoter in the presence of tetracycline/doxycycline. To facilitate testing the system, we generated a knockin reporter mouse in which the firefly luciferase gene replaces the Cox2 coding region. Cox2 promoter activation in cultured cells from triple transgenic mice containing the luciferase allele, the shRNA and the transactivator transgene resulted in robust luciferase and COX-2 expression that was reversibly down-regulated by doxycycline administration. In vivo, using a skin inflammation-model, both luciferase and COX-2 expression were inhibited over 80% in mice that received doxycycline in their diet, leading to a significant reduction of infiltrating leukocytes. In summary, using inducible RNA interference to target COX-2 expression, we demonstrate potent, reversible Cox2 gene silencing in vivo. This system should provide a valuable tool to analyze cell type-specific roles for COX-2.

Zaiss, Anne K.; Zuber, Johannes; Chu, Chun; Machado, Hidevaldo B.; Jiao, Jing; Catapang, Arthur B.; Ishikawa, Tomo-o; Gil, Jose S.; Lowe, Scott W.; Herschman, Harvey R.

2014-01-01

275

COX-2 Gene Promoter Methylation in Patients Infected with Helicobacter Pylori  

PubMed Central

Cyclooxygenase (COX) plays a critical role in peptic ulcer development. COX-2 contains CpG islands in promoter area, which suggests possible epigenetic mechanisms of gene silencing. We evaluated COX-2 gene promoter methylation levels in the gastric mucosa of patients with various gastric diseases. DNA was extracted from endoscopic biopsy materials collected from the gastric mucosa. The methylation levels of the COX-2 gene promoter were measured quantitatively by using pyrosequencing. COX-2 mRNA expression in Kato III and AGS cells was measured using real-time PCR. COX-2 gene promoter methylation levels were significantly higher in Helicobacter pylori (HP)-positive cases than in HP-negative cases (27.5% vs. 8.1%, respectively, P < 0.001). COX-2 gene promoter methylation levels in patients in whom HP was successfully eradicated were significantly lower than those in HP-positive cases (18.7% vs. 27.5%, respectively, P < 0.01). We then investigated the effects of COX-2 gene promoter methylation on its mRNA expression in vitro. COX-2 mRNA expression was not observed in Kato III cells, despite the addition of the protein kinase C stimulator ?-phorbol 12,13-dibutyrate (PDBu). COX-2 expression was observed after the addition of the demethylating agent 5-Aza-dC and was enhanced by PDBu. HP infection caused a significant increase in the methylation levels of the COX-2 gene promoter in the gastric mucosa. In addition to transcriptional regulation, COX-2 expression is regulated through epigenetic mechanisms.

Michikawa, Yosuke; Yasuda, Hiroshi; Watanabe, Yoshiyuki; Oikawa, Ritsuko; Ohishi, Yoshichika; Maehata, Tadateru; Itoh, Fumio

2013-01-01

276

Prognostic Significance and Clinicopathological Associations of COX-2 SNP in Patients with Nonsmall Cell Lung Cancer  

PubMed Central

Background. To further improve the screening, diagnosis, and therapy of patients with nonsmall cell lung cancer (NSCLC) additional diagnostic tools are urgently needed. Gene expression of Cyclooxygenase-2 (COX-2) has been linked to prognosis in patients with NSCLC. The role of the COX-2 926G>C Single Nucleotide Polymorphism (SNP) in patients with NSCLC remains unclear. The aim of this study was to investigate the potential of the COX-2 926G>C SNP as a molecular marker in this disease. Methods. COX-2 926G>C SNP was analyzed in surgically resected tumor tissue of 85 patients with NSCLC using a PCR-based RFLP technique. Results. The COX-2 926G>C SNP genotypes were detected with the following frequencies: GG n = 62 (73%), GC n = 20 (23%), CC n = 3 (4%). There were no associations between COX-2 SNP genotype and histology, grading or gender detectable. COX-2 SNP was significantly associated with tumor stage (P = .032) and lymph node status (P = .016, Chi-square test). With a median followup of 85.9 months, the median survival was 59.7 months. There were no associations seen between the COX-2 SNP genotype and patients prognosis. Conclusions. The COX-2 926G>C SNP is detectable at a high frequency in patients with NSCLC. The COX-2 926G>C SNP genotype is not a prognostic molecular marker in this disease. However, patients with the GC or CC genotype seem more susceptible to lymph node metastases and higher tumor stage than patients with the GG genotype. The results suggest COX-2 926G>C SNP as a molecular marker for lymph node involvement in this disease.

Grimminger, Peter P.; Stohlmacher, Jan; Vallbohmer, Daniel; Schneider, Paul M.; Holscher, Arnulf H.; Metzger, Ralf; Danenberg, Peter V.; Brabender, Jan

2009-01-01

277

Prognostic Significance and Clinicopathological Associations of COX-2 SNP in Patients with Nonsmall Cell Lung Cancer.  

PubMed

Background. To further improve the screening, diagnosis, and therapy of patients with nonsmall cell lung cancer (NSCLC) additional diagnostic tools are urgently needed. Gene expression of Cyclooxygenase-2 (COX-2) has been linked to prognosis in patients with NSCLC. The role of the COX-2 926G>C Single Nucleotide Polymorphism (SNP) in patients with NSCLC remains unclear. The aim of this study was to investigate the potential of the COX-2 926G>C SNP as a molecular marker in this disease. Methods. COX-2 926G>C SNP was analyzed in surgically resected tumor tissue of 85 patients with NSCLC using a PCR-based RFLP technique. Results. The COX-2 926G>C SNP genotypes were detected with the following frequencies: GG n = 62 (73%), GC n = 20 (23%), CC n = 3 (4%). There were no associations between COX-2 SNP genotype and histology, grading or gender detectable. COX-2 SNP was significantly associated with tumor stage (P = .032) and lymph node status (P = .016, Chi-square test). With a median followup of 85.9 months, the median survival was 59.7 months. There were no associations seen between the COX-2 SNP genotype and patients prognosis. Conclusions. The COX-2 926G>C SNP is detectable at a high frequency in patients with NSCLC. The COX-2 926G>C SNP genotype is not a prognostic molecular marker in this disease. However, patients with the GC or CC genotype seem more susceptible to lymph node metastases and higher tumor stage than patients with the GG genotype. The results suggest COX-2 926G>C SNP as a molecular marker for lymph node involvement in this disease. PMID:20016751

Grimminger, Peter P; Stöhlmacher, Jan; Vallböhmer, Daniel; Schneider, Paul M; Hölscher, Arnulf H; Metzger, Ralf; Danenberg, Peter V; Brabender, Jan

2009-01-01

278

Selective JAK inhibitors in development for rheumatoid arthritis.  

PubMed

Introduction: The JAK kinases are a family of four tyrosine receptor kinases that play a pivotal role in cytokine receptor signalling pathways via their interaction with signal transducers and activators of transcription proteins. Selective inhibitors of JAK kinases are viewed as of considerable potential as disease-modifying anti-inflammatory drugs for the treatment of rheumatoid arthritis. Areas covered: This article provides a review of the clinical development and available clinical results for those JAK inhibitors currently under investigation. Phase II data for four JAK inhibitors (baricitinib, decernotinib, filgotinib and INCB-039110) are contrasted with that reported for the recently approved JAK inhibitor tofacitinib. The preclinical data on these, in addition to peficitinib, ABT-494, INCB-047986 and AC-410 are also discussed, as are some of the inhibitors in preclinical development. Expert opinion: JAK inhibitors are effective in the treatment of rheumatoid arthritis as evidenced by several inhibitors enabling the majority of treated patients to achieve ACR20 responses, with baricitinib and INCB-039110 both effective when administered once daily. JAK inhibitors differ in isoform specificity profiles, with good efficacy achievable by selective inhibition of either JAK1 (filgotinib or INCB-039110) or JAK3 (decernotinib). It remains to be seen what selectivity provides the optimal side-effect profile and to what extent inhibition of JAK2 should be avoided. PMID:24818516

Norman, Peter

2014-08-01

279

Dietary Zinc Modulation of COX2 Expression and Lingual and Esophageal Carcinogenesis in Rats  

Microsoft Academic Search

Background: Cancer of the upper aerodigestive tract, includ- ing esophageal and tongue carcinomas, is a major cause of cancer deaths worldwide. Esophageal and tongue cancers have both been associated with dietary zinc deficiency (ZD), and cyclooxygenase (COX-2) is often overexpressed in these cancers. Using rat models, we examined whether zinc regu- lates COX-2 expression in these cancers. Method: Expression of

Louise Y. Y. Fong; Liang Zhang; Yubao Jiang; John L. Farber

2005-01-01

280

Role of PPAR? in COX-2 activation in mycobacterial pulmonary inflammation  

PubMed Central

Preliminary studies show that intranasal (i.n.) administration of BCG in mice induces M1 activation of alveolar macrophages (MØ) that increase TNF-? production and cyclooxygenase-2 (COX-2) expression but reduce constitutive peroxisome proliferator-activated receptor gamma (PPAR?) expression. However, COX-2 is catalytically inactive for prostaglandin E2 release, unlike COX-2 active in M1 activation in vitro by BCG. In this study, we determined the role of PPAR? for BCG-induced M1 activation in vivo and in vitro. We found that treatment of mice with GW9662, a PPAR? antagonist, prior to i.n. BCG, partially restored PPAR? expression, and decreased TNF-? production and COX-2 expression. But COX-2 was still inactive. The decreased effects on TNF-? and COX-2 were also observed when alveolar MØ were treated in vitro with GW9662/BCG, but COX-2 was still active. Our results indicate that PPAR? up-regulates M1 activation of alveolar MØ, but inactive COX-2 formation is independent of PPAR? in mycobacterial pulmonary inflammation.

Kogiso, Mari; Shinohara, Tsutomu; Dorey, C. Kathleen; Shibata, Yoshimi

2012-01-01

281

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

PubMed

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

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

2013-01-01

282

CYCLOOXYGENASE 2 (COX2) SUPPRESSES FORMATION OF ADHERENS JUNCTIONS AND STRESS FIBERS  

Microsoft Academic Search

INTRODUCTION. Cyclooxygenase 2 (COX-2) is a key enzyme in the production of prostaglandins (PGs) and represents an important target for treatment and prevention of colorectal cancer (1). However, the molecular mechanisms by which COX-2 regulates colon epithelial cell morphology and stress fiber formation are not well understood. The normal morphology of colon epithelial cells is established and maintained by adherens

Yu-Wen E. Chang; Terry W. Chance; Jerry W. Marlin; Rolf Jakobi

283

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

PubMed Central

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.

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

2013-01-01

284

Screening of selective histone deacetylase inhibitors by proteochemometric modeling  

PubMed Central

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.

2012-01-01

285

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

PubMed

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 E2 (PGE2) 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 ?M 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. PGE2 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, PGE2, cellular proliferation and MEK/MAPK activation, implicating this pathway in regulating miR-143 expression. PMID:23973710

Pham, Hung; Rodriguez, C Ekaterina; 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

286

Potency and selectivity of carprofen enantiomers for inhibition of bovine cyclooxygenase in whole blood assays.  

PubMed

Whole blood in vitro assays were used to determine the potency and selectivity of carprofen enantiomers for inhibition of the isoforms of cyclooxygenase (COX), COX-1 and COX-2, in the calf. S(+)-carprofen possessed preferential activity for COX-2 inhibition but, because the slopes of inhibition curves differed, the COX-1:COX-2 inhibition ratio decreased from 9.04:1 for inhibitory concentration (IC)10 to 1.84:1 for IC95. R(-) carprofen inhibited COX-2 preferentially only for low inhibition of the COX isoforms (IC10 COX-1:COX-2=6.63:1), whereas inhibition was preferential for COX-1 for a high level of inhibition (IC95 COX-1:COX-2=0.20:1). S(+) carprofen was the more potent inhibitor of COX isoforms; potency ratios S(+):R(-) carprofen were 11.6:1 for IC10 and 218:1 for IC90. Based on serum concentrations of carprofen enantiomers obtained after administration of a therapeutic dose of 1.4 mg/kg to calves subcutaneously, S(+)-carprofen concentrations exceeded the in vitro IC80 COX-2 value for 32 h and the IC20 for COX-1 for 33 h. The findings are discussed in relation to efficacy and safety of carprofen in calves. PMID:22703724

Brentnall, Claire; Cheng, Zhangrui; McKellar, Quintin A; Lees, Peter

2012-12-01

287

Peripheral administration of morphine attenuates postincisional pain by regulating macrophage polarization through COX-2-dependent pathway  

PubMed Central

Background Macrophage infiltration to inflammatory sites promotes wound repair and may be involved in pain hypersensitivity after surgical incision. We recently reported that the development of hyperalgesia during chronic inflammation is regulated by macrophage polarity, often referred to as proinflammatory (M1) or anti-inflammatory (M2) macrophages. Although opioids such as morphine are known to alter the inflammatory milieu of incisional wounds through interactions with immunocytes, the macrophage-mediated effects of morphine on the development of postincisional pain have not been well investigated. In this study, we examined how morphine alters pain hypersensitivity through phenotypic shifts in local macrophages during the course of incision-induced inflammation. Results Local administration of morphine in the early phase, but not in the late phase alleviated mechanical hyperalgesia, and this effect was reversed by clodronate-induced peripheral depletion of local macrophages. At the morphine-injected incisional sites, the number of pro-inflammatory F4/80+iNOS+M1 macrophages was decreased during the course of pain development whereas increased infiltration of wound healing F4/80+CD206+M2 macrophages was observed during the early phase. Morphine increased the gene expression of endogenous opioid, proenkephalin, and decreased the pronociceptive cytokine, interleukin-1?. Heme oxygenase (HO)-1 promotes the differentiation of macrophages to the M2 phenotype. An inhibitor of HO-1, tin protoporphyrin reversed morphine-induced analgesic effects and the changes in macrophage phenotype. However, local expression levels of HO-1 were not altered by morphine. Conversely, cyclooxygenase (COX)-2, primarily produced from peripheral macrophages in acute inflammation states, was up-regulated in the early phase at morphine-injected sites. In addition, the analgesic effects and a phenotype switching of infiltrated macrophages by morphine was reversed by local administration of a COX inhibitor, indomethacin. Conclusions Local administration of morphine alleviated the development of postincisional pain, possibly by altering macrophage polarity at the incisional sites. A morphine-induced shift in macrophage phenotype may be mediated by a COX-2-dependent mechanism. Therefore, ?-opioid receptor signaling in macrophages may be a potential therapeutic target during the early phase of postincisional pain development.

2014-01-01

288

Wnt/?-Catenin Signaling Enhances Cyclooxygenase-2 (COX2) Transcriptional Activity in Gastric Cancer Cells  

PubMed Central

Background Increased expression of the cyclooxygenase-2 enzyme (COX2) is one of the main characteristics of gastric cancer (GC), which is a leading cause of death in the world, particularly in Asia and South America. Although the Wnt/?-catenin signaling pathway has been involved in the transcriptional activation of the COX2 gene, the precise mechanism modulating this response is still unknown. Methodology/Principal Findings Here we studied the transcriptional regulation of the COX2 gene in GC cell lines and assessed whether this phenomenon is modulated by Wnt/?-catenin signaling. We first examined the expression of COX2 mRNA in GC cells and found that there is a differential expression pattern consistent with high levels of nuclear-localized ?-catenin. Pharmacological treatment with either lithium or valproic acid and molecular induction with purified canonical Wnt3a significantly enhanced COX2 mRNA expression in a dose- and time-dependent manner. Serial deletion of a 1.6 Kbp COX2 promoter fragment and gain- or loss-of-function experiments allowed us to identify a minimal Wnt/?-catenin responsive region consisting of 0.8 Kbp of the COX2 promoter (pCOX2-0.8), which showed maximal response in gene-reporter assays. The activity of this pCOX2-0.8 promoter region was further confirmed by site-directed mutagenesis and DNA-protein binding assays. Conclusions/Significance We conclude that the pCOX2-0.8 minimal promoter contains a novel functional T-cell factor/lymphoid enhancer factor (TCF/LEF)-response element (TBE Site II; -689/-684) that responds directly to enhanced Wnt/?-catenin signaling and which may be important for the onset/progression of GC.

Nunez, Felipe; Bravo, Soraya; Cruzat, Fernando; Montecino, Martin; De Ferrari, Giancarlo V.

2011-01-01

289

Ex vivo assay to determine the cyclooxygenase selectivity of non-steroidal anti-inflammatory drugs  

PubMed Central

In this study we describe experiments to establish ex vivo the selectivity of non-steroidal anti-inflammatory drugs (NSAIDs) given in vivo.Anaesthetised (Inactin, 120?mg?kg?1) male Wistar rats (220–250?g) received an i.v. dose of one of the following compounds (dose mg?kg?1): aspirin (20), diclofenac (3), L-745,337 (30), nimesulide (15), salicylate (20), sulindac (10). Blood samples were taken before and up to 6?h after dosing and the plasma obtained from it was tested for its ability to inhibit prostanoid formation in IL-1?-treated A549 cells (COX-2 system) and human washed platelets (COX-1 system). For control the same compounds were also added directly to the assay systems.All drugs, except sodium salicylate, inhibited COX-1 and COX-2 when added directly to the test systems. Plasma from aspirin-treated rats was without effect on either COX-1 or COX-2, consistent with the rapid in vivo metabolism to salicylate. Conversely, plasma from sulindac-treated rats inhibited COX-1 and COX-2 with potencies according with in vivo metabolism to sulindac sulphide. Diclofenac was COX-1/2 non-selective when tested in vitro, but a slightly preferential inhibitor of COX-2 when tested ex vivo. Nimesulide was confirmed as preferential inhibitor of COX-2 both in vitro and ex vivo. L-745,337 was a selective COX-2 inhibitor when tested in vitro or ex vivo.In conclusion, our experiments show clearly (a) NSAIDs inactivation, (b) activation of pro-drugs, and (c) NSAIDs selectivity. Our assay provides useful information about the selectivity of NSAIDs that could be extended by the analysis of plasma samples taken from humans similarly treated with test drugs.

Giuliano, Francesco; Warner, Timothy D

1999-01-01

290

Triazaspirodimethoxybenzoyls as Selective Inhibitors of Mycobacterial Lipoamide Dehydrogenase  

SciTech Connect

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.

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

2010-06-25

291

Triazaspirodimethoxybenzoyls as selective inhibitors of mycobacterial lipoamide dehydrogenase†#  

PubMed Central

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 Å 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 homolog were predicted to contribute both to inhibitor binding and species selectivity, as confirmed for 3 residues by analysis of the corresponding mutant Mtb Lpd proteins. Thus non-conservation of residues lining the electron-transfer tunnel in Mtb Lpd can be exploited for development of species-selective Lpd inhibitors.

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

2010-01-01

292

Identification of selective inhibitors of cyclin dependent kinase 4.  

PubMed

A new structural type of kinase inhibitor, containing a benzocarbazole nucleus, has been identified. Members of the series are selective for inhibition of the cyclin dependent kinase family of enzymes. Although the cdks are highly homologous, representatives of the series showed intra-cdk selectivities, especially for cdk4. SAR studies elucidated the important features of the molecules for inhibition. PMID:11514172

Carini, D J; Kaltenbach, R F; Liu, J; Benfield, P A; Boylan, J; Boisclair, M; Brizuela, L; Burton, C R; Cox, S; Grafstrom, R; Harrison, B A; Harrison, K; Akamike, E; Markwalder, J A; Nakano, Y; Seitz, S P; Sharp, D M; Trainor, G L; Sielecki, T M

2001-08-20

293

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

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 selective COX-2 inhibition by amarogentin and endorses the possibility of obtaining efficient, futuristic and targeted therapeutic agents for relieving inflammation and malignancy from this phytochemical source.

Sundar, Durai; Thorat, Sunil S.

2014-01-01

294

Discovery of a Potent And Selective Aurora Kinase Inhibitor  

SciTech Connect

This communication describes the discovery of a novel series of Aurora kinase inhibitors. Key SAR and critical binding elements are discussed. Some of the more advanced analogues potently inhibit cellular proliferation and induce phenotypes consistent with Aurora kinase inhibition. In particular, compound 21 (SNS-314) is a potent and selective Aurora kinase inhibitor that exhibits significant activity in pre-clinical in vivo tumor models.

Oslob, J.D.; Romanowski, M.J.; Allen, D.A.; Baskaran, S.; Bui, M.; Elling, R.A.; Flanagan, W.M.; Fung, A.D.; Hanan, E.J.; Harris, S.; Heumann, S.A.; Hoch, U.; Jacobs, J.W.; Lam, J.; Lawrence, C.E.; McDowell, R.S.; Nannini, M.A.; Shen, W.; Silverman, J.A.; Sopko, M.M.; Tangonan, B.T.

2009-05-21

295

Design and synthesis of potent, selective inhibitors of matriptase.  

PubMed

Matriptase is a member of the type II transmembrane serine protease family. Several studies have reported deregulated matriptase expression in several types of epithelial cancers, suggesting that matriptase constitutes a potential target for cancer therapy. We report herein a new series of slow, tight-binding inhibitors of matriptase, which mimic the P1-P4 substrate recognition sequence of the enzyme. Preliminary structure-activity relationships indicate that this benzothiazole-containing RQAR-peptidomimetic is a very potent inhibitor and possesses a good selectivity for matriptase versus other serine proteases. A molecular model was generated to elucidate the key contacts between inhibitor 1 and matriptase. PMID:24900505

Colombo, Eloïc; Désilets, Antoine; Duchêne, Dominic; Chagnon, Félix; Najmanovich, Rafael; Leduc, Richard; Marsault, Eric

2012-07-12

296

Design and Synthesis of Potent, Selective Inhibitors of Matriptase  

PubMed Central

Matriptase is a member of the type II transmembrane serine protease family. Several studies have reported deregulated matriptase expression in several types of epithelial cancers, suggesting that matriptase constitutes a potential target for cancer therapy. We report herein a new series of slow, tight-binding inhibitors of matriptase, which mimic the P1–P4 substrate recognition sequence of the enzyme. Preliminary structure–activity relationships indicate that this benzothiazole-containing RQAR-peptidomimetic is a very potent inhibitor and possesses a good selectivity for matriptase versus other serine proteases. A molecular model was generated to elucidate the key contacts between inhibitor 1 and matriptase.

2012-01-01

297

Prostacyclin mediates endothelial COX-2-dependent neuroprotective effects during excitotoxic brain injury  

PubMed Central

In a previous study, we found that intracerebral administration of excitotoxin (RS)-(tetrazole-5yl) glycine caused increased neural damage in the brain in an endothelial COX-2 deleted mouse line (Tie2Cre COX-2flox/flox). In this study, we investigated whether prostacyclin might mediate this endothelial COX-2-dependent neuroprotection. Administration of excitotoxin into the striatum induced the production of prostacyclin (PGI2) in wild type, but not in endothelial COX-2 deleted mice. Inhibition of PGI2 synthase exacerbated brain lesions induced by the excitotoxin in wild type, but not in endothelial COX-2 deleted mice. Administration of a PGI2 agonist reduced neural damage in both wild type and endothelial COX-2 deleted mice. Increased PGI2 synthase expression was found in infiltrating neutrophils. In an ex vivo assay, PGI2 reduced the excitotoxin-induced calcium influx into neurons, suggesting a cellular mechanism for PGI2 mediated neuroprotection. These results reveal that PGI2 mediates endothelial COX-2 dependent neuroprotection.

An, Ying; Belevych, Natalya; Wang, Yufen; Zhang, Hao; Nasse, Jason S; Herschman, Harvey; Chen, Qun; Tarr, Andrew; Liu, Xiaoyu; Quan, Ning

2014-01-01

298

Carvacrol, a component of thyme oil, activates PPAR? and ? and suppresses COX-2 expression[S  

PubMed Central

Cyclooxygenase-2 (COX-2), the rate-limiting enzyme in prostaglandin biosynthesis, plays a key role in inflammation and circulatory homeostasis. Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors belonging to the nuclear receptor superfamily and are involved in the control of COX-2 expression, and vice versa. Here, we show that COX-2 promoter activity was suppressed by essential oils derived from thyme, clove, rose, eucalyptus, fennel, and bergamot in cell-based transfection assays using bovine arterial endothelial cells. Moreover, from thyme oil, we identified carvacrol as a major component of the suppressor of COX-2 expression and an activator of PPAR? and ?. PPAR?-dependent suppression of COX-2 promoter activity was observed in response to carvacrol treatment. In human macrophage-like U937 cells, carvacrol suppressed lipopolysaccharide-induced COX-2 mRNA and protein expression, suggesting that carvacrol regulates COX-2 expression through its agonistic effect on PPAR?. These results may be important in understanding the antiinflammatory and antilifestyle-related disease properties of carvacrol.

Hotta, Mariko; Nakata, Rieko; Katsukawa, Michiko; Hori, Kazuyuki; Takahashi, Saori; Inoue, Hiroyasu

2010-01-01

299

Cyclooxygenase-2 (COX-2): first immunohistochemical marker distinguishing early cutaneous melanomas from benign melanocytic skin tumours.  

PubMed

We have reported recently that changes in expression level of COX-2 are correlated with development and progression of human melanoma. In this study, we investigated whether the COX-2 expression level might be a useful immunohistochemical marker for distinguishing cutaneous melanomas from benign melanocytic lesions. Up to now, immunohistochemical markers have not ensured satisfactory sensitivity and specificity of differential pathologic diagnosis of melanoma. The expression of COX-2 was determined immunohistochemically in formalin-fixed, paraffin-embedded specimens of 33 early Clark I/II melanomas and 58 naevi. Mean COX-2 expression in melanomas was significantly stronger than in naevi (P approximately 10(-13)). A simple diagnostic algorithm using threshold values of the COX-2 expression level allows for differentiation between early melanomas and naevi with high sensitivity (Se) and specificity (Sp) (for Se between 91 and 100%, Sp values change between 96.5 and 51.7%). Areas under the receiver operating characteristic curves were, respectively, 0.97+/-0.02 and 0.86+/-0.04 for the COX-2 expression in central and border regions of the lesions. For all the melanomas (not only the early ones),the respective areas under the ROC curve values were 0.98+/-0.01 and 0.97+/-0.02. In conclusion, COX-2 is the first immunohistochemical marker that allows the distinguishing of early melanomas from benign melanocytic lesions with both high sensitivity and specificity. PMID:17505259

Chwirot, Barbara W; Ku?bicki, ?ukasz

2007-06-01

300

Prostacyclin mediates endothelial COX-2-dependent neuroprotective effects during excitotoxic brain injury.  

PubMed

In a previous study, we found that intracerebral administration of excitotoxin (RS)-(tetrazole-5yl) glycine caused increased neural damage in the brain in an endothelial COX-2 deleted mouse line (Tie2Cre COX-2(flox/flox) ). In this study, we investigated whether prostacyclin might mediate this endothelial COX-2-dependent neuroprotection. Administration of excitotoxin into the striatum induced the production of prostacyclin (PGI2) in wild type, but not in endothelial COX-2 deleted mice. Inhibition of PGI2 synthase exacerbated brain lesions induced by the excitotoxin in wild type, but not in endothelial COX-2 deleted mice. Administration of a PGI2 agonist reduced neural damage in both wild type and endothelial COX-2 deleted mice. Increased PGI2 synthase expression was found in infiltrating neutrophils. In an ex vivo assay, PGI2 reduced the excitotoxin-induced calcium influx into neurons, suggesting a cellular mechanism for PGI2 mediated neuroprotection. These results reveal that PGI2 mediates endothelial COX-2 dependent neuroprotection. PMID:24971026

An, Ying; Belevych, Natalya; Wang, Yufen; Zhang, Hao; Nasse, Jason S; Herschman, Harvey; Chen, Qun; Tarr, Andrew; Liu, Xiaoyu; Quan, Ning

2014-01-01

301

Cell proliferation activity unrelated to COX-2 expression in ovarian tumors.  

PubMed

The objective of this study was to assess the expression of Cyclooxygenase-2 (COX-2) and cell proliferation activity (Ki67 expression) in benign, borderline, and malignant serous and mucinous ovarian tumors. Expression of COX-2 and Ki67 proteins were evaluated by immunohistochemistry, in paraffin-embedded sections of ovarian epithelial tumors. The study included 113 serous (67 benign, 15 borderline, and 31 malignant) and 85 mucinous (48 benign, 28 borderline, and 9 malignant) tumors, removed from women who underwent laparotomy between January 1997 and December 2003. From benign to malignant tumors, there was a progressive positive trend in COX-2 expression in both serous and mucinous tumors, more evident in mucinous ones (P < 0.001). Comparing histologic types, COX-2 expression was more prominent in serous than in mucinous benign tumors (P < 0.01), but this difference was not significant in the borderline (P= 0.11) or malignant categories (P= 0.71). There was a progressive Ki67 positivity in line with the tumor histologic gradient for both serous (P < 0.01) and mucinous lesions (P < 0.01), but this increasing expression did not correlate with COX-2 expression in the present series (P= 0.78). There was a higher COX-2 expression in serous ovarian adenomas than in mucinous ones. COX-2 positivity increases in line with the morphologic gradient, from benign to malignant in both histologic types, but it was more prominent in mucinous lesions, pointing to different oncogenic pathways related to different histologic types. A correlation between the expression of COX-2 and Ki67 was not found, suggesting that COX-2 may be required for carcinogenesis, but this pathway is not responsible for cell proliferation in ovarian tumors. PMID:17504375

Yoshida, A; Sarian, L O; Andrade, L A L A; Pignataro, F; Pinto, G A; Derchain, S F M

2007-01-01

302

Methylation status and overexpression of COX-2 in Tunisian patients with ductal invasive breast carcinoma.  

PubMed

Inflammation and hormonal signalling induce the cyclooxygenase-2 (COX-2) expression in solid tumours including breast cancer, which in turn affects cell proliferation, apoptosis and metastasis. The aim of this study was to investigate the expression of COX-2 and its association with clinical parameters, patient's survival, hormones receptors (oestrogen, progesterone), ERBB2 and TP53 expression in 83 cases of infiltrating ductal breast carcinomas. Moreover, the methylation status at the CpG islands of the COX-2 gene promoter was also explored in 70 specimens. We showed that tumours exhibiting moderate to intense COX-2 immunostaining were significantly more frequent in patients over 45 years old (p = 0.027). Moreover, a high level of COX-2 expression correlated with a shorter survival time (p log-rank = 0.04) and was an independent prognostic factor (p = 0.022; HR 6.4; 95% CI = 1.3-31.4). On the other hand, hypermethylation of the COX-2 gene promoter was observed in 27% of cases and strongly associated with smaller tumours (<5 cm, p = 0.011). Furthermore, patients with methylated COX-2 pattern have a better 4-year disease-free survival (p = 0.022) as well as a prolonged overall survival (p log-rank test = 0.034). In conclusion, we showed that high COX-2 expression was associated with reduced survival and was an independent prognostic factor. However, hypermethylation of the COX-2 promoter correlated with a better overall survival in Tunisian patients with breast carcinoma. PMID:21153458

Karray-Chouayekh, Sondes; Trifa, Fatma; Khabir, Abdelmajid; Boujelbene, Noureddine; Sellami-Boudawara, Tahia; Daoud, Jamel; Frikha, Mounir; Gargouri, Ali; Mokdad-Gargouri, Raja

2011-06-01

303

FGFR1-induced epithelial to mesenchymal transition through MAPK/PLC?/COX-2-mediated mechanisms.  

PubMed

Tumour invasion and metastasis is the most common cause of death from cancer. For epithelial cells to invade surrounding tissues and metastasise, an epithelial-mesenchymal transition (EMT) is required. We have demonstrated that FGFR1 expression is increased in bladder cancer and that activation of FGFR1 induces an EMT in urothelial carcinoma (UC) cell lines. Here, we created an in vitro FGFR1-inducible model of EMT, and used this model to identify regulators of urothelial EMT. FGFR1 activation promoted EMT over a period of 72 hours. Initially a rapid increase in actin stress fibres occurred, followed by an increase in cell size, altered morphology and increased migration and invasion. By using site-directed mutagenesis and small molecule inhibitors we demonstrated that combined activation of the mitogen activated protein kinase (MAPK) and phospholipase C gamma (PLC?) pathways regulated this EMT. Actin stress fibre formation was regulated by PLC? activation, and was also important for the increase in cell size, migration and altered morphology. MAPK activation regulated migration and E-cadherin expression, indicating that combined activation of PLC? and MAPK is required for a full EMT. We used expression microarrays to assess changes in gene expression downstream of these signalling cascades. COX-2 was transcriptionally upregulated by FGFR1 and caused increased intracellular prostaglandin E(2) levels, which promoted migration. In conclusion, we have demonstrated that FGFR1 activation in UC cells lines promotes EMT via coordinated activation of multiple signalling pathways and by promoting activation of prostaglandin synthesis. PMID:22701738

Tomlinson, Darren C; Baxter, Euan W; Loadman, Paul M; Hull, Mark A; Knowles, Margaret A

2012-01-01

304

Inhibition of DNA repair as a mechanism of enhanced radioresponse of head and neck carcinoma cells by a selective cyclooxygenase-2 inhibitor, celecoxib  

SciTech Connect

Purpose: Previously, we reported that inhibitors of cyclooxygenase-2 (COX-2) enzyme enhanced murine and human tumor cell response to radiation in vitro and in vivo. However, the molecular mechanisms mediating the effects of COX-2 inhibitors are not clear. The present study was designed to investigate the ability of celecoxib, a selective COX-2 inhibitor, to sensitize human head-and-neck cancer cell line, HN5, to radiation, and examine its effects on DNA repair, which may be a potential mechanism of radiosensitization. Methods and Materials: Cells were assessed for the effect of celecoxib (5-50 {mu}M), by 3-[4,5-dimethylthiozol-2-yl]-2,5-diphenyltetrazolium bromide assay for growth inhibition and by clonogenic cell survival assay for the radiosensitizing effect. Kinase assay and Western analysis were conducted to assess the effect of celecoxib on DNA-dependent protein kinase catalytic subunit (PKcs) and Ku proteins. Electrophoretic mobility shift assays (EMSA) were performed to determine the DNA-binding activity of Ku/DNA-PKcs protein complex and nuclear factor kappa B (NF{kappa}B). Results: Celecoxib (10 and 50 {mu}M, for 2 days) inhibited the HN5 cell growth and significantly enhanced the cell radiosensitivity in a dose-dependent manner. It also reduced the shoulder region on the radiation-survival curve, suggesting that inhibition of DNA repair processes may have occurred. Western blot analysis demonstrated that celecoxib downregulated the expression of Ku70 protein and inhibited the kinase activity of DNA-PKcs, which are involved in the double-stranded DNA-break repair machinery. By EMSA, it was further shown that celecoxib reduced DNA-binding activity of Ku/DNA-PKcs protein complex. In addition, celecoxib inhibited the constitutively active NF{kappa}B and the radiation-induced NF{kappa}B in HN5 cells, suggesting that NF{kappa}B may play a role in mediating the effects of celecoxib. Conclusions: Celecoxib strongly enhanced the sensitivity of HN5 carcinoma cells to radiation, which, mechanistically, can be attributed to the inhibition of DNA repair processes in radiation-damaged cells.

Raju, Uma [Department of Experimental Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)]. E-mail: uraju@mdanderson.org; Ariga, Hisanori [Department of Radiation Oncology, Miyagi Cancer Center, Miyagi (Japan); Dittmann, Klaus [Department of Radiation Oncology, Eberhard Karls-University, Tubingen (Germany); Nakata, Eiko [Department of Radiology, Tohoku University School of Medicine, Sendai (Japan); Ang, Kian K. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Milas, Luka [Department of Experimental Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

2005-10-01

305

Antiproliferative effects of selective cyclooxygenase-2 inhibitor modulated by nimotuzumab in estrogen-dependent breast cancer cells.  

PubMed

Breast cancer is the most common malignancy in women, and many breast cancer patients fail conventional treatment strategies of chemotherapy, radiation, and antiestrogen therapy. Research into the molecular pathways and biomarkers involved in the development of breast cancer should yield information that will guide therapeutic decisions. Epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) are involved in the carcinogenesis of breast cancer and exist tight crosstalk with estrogen receptor (ER) pathway. Combination of EGFR and COX-2 inhibitors, therefore, could be an effective strategy for reducing cell growth in estrogen-dependent breast cancer. In order to verify the effects of EGFR and COX-2 inhibitors, breast cancer cells MCF-7 and SKBR-3 were characterized for receptors status and then treated with respective inhibitors (nimotuzumab and celecoxib) alone and in combination. Both cell lines were sensitive to celecoxib, but not to nimotuzumab. However, combination of two drugs demonstrated synergistic effects on cell killing. Moreover, association of two drugs resulted in SKBR-3 cells, a further G0/G1 phase arrest than one drug alone. Downregulation of p-EGFR, p-Akt, p-mTOR, and amplified in breast cancer 1 (AIB1) were observed in both cell lines, and upregulation of E-cadherin was only found in MCF-7, after treatment with single agent or in combination. These studies suggest that nimotuzumab and celecoxib exert synergistic antiproliferation effects in breast cancer, which partly correlates with ER status. Due to Akt/mTOR, EMT and AIB1 pathways participate in this process, therefore, E-cadherin and AIB1 may be considered as possible biomarkers to predict response in ER-positive breast cancer cells treated with EGFR and COX-2 inhibitors. PMID:22252523

Wang, Ying-Xue; Gao, Jin-Xiang; Wang, Xiu-Yun; Zhang, Li; Liu, Chang-Mei

2012-08-01

306

Role of Cyclooxygenase 2 (COX-2) in Prognosis of Breast Cancer.  

PubMed

COX-2 regulates tumour growth, invasion and metastasis in breast cancer. This study investigated the association between COX-2 expression in human breast cancer versus the expression of ER, PR, HER-2/neu, as well as its association with other established prognostic indicators like age, menopausal status, tumour size, lymph nodal status, stage, grade, NPI and histological subtype, and aims to validate the role of overexpression of COX-2 as a prognostic marker in patients with breast cancer in Indian subcontinent. In this hospital based study of 123 breast cancer patients (Group-A) and 76 female patients with benign breast disease (Group-B) attending a Comprehensive Breast Clinic at a reputed institute in Eastern India, COX-2 protein expression was measured from breast tissue using the Western Blot Technique. COX-2 mRNA expression was measured by RT-PCR Technique. ER, PR and HER-2/neu status was measured by immunohistochemistry methods. COX-2 was not expressed in the control group. The proportion of COX-2 positive tumours was significantly higher in patients of age >50 years [52(91.2 %), p?COX-2 expression was seen in ER-negative [66(95.7 %), p?COX-2 positivity was found to be 2.74 times more for postmenopausal status, 6.90 times more for large size tumours (? 2.5), 34.37 times more for node positive tumours, 9.26 times more with ER negative patients and 5.88 times more for PR negative patients. COX-2 expression is associated with established indicators of poor prognosis such as postmenopausal status, age >50 year, advanced stage of disease, large tumour size, higher grade, lymph node metastasis, NPI???5.4, ER negativity, PR negativity and HER-2/neu positivity. Thus, COX-2 expression implies aggressive tumour biology, and may play an important role as a prognostic marker. PMID:24669166

Jana, Debarshi; Sarkar, Diptendra Kumar; Ganguly, Suvro; Saha, Shilpi; Sa, Gaurisankar; Manna, Asim Kumar; Banerjee, Abhirup; Mandal, Syamsundar

2014-03-01

307

15-deoxy-delta 12,14-prostaglandin J(2) inhibits the synthesis of the acute phase protein SIP24 in cartilage: Involvement of COX-2 in resolution of inflammation.  

PubMed

We previously demonstrated that, in the MC615 cartilage cell line, the p38/NF-kB pathway is activated both during differentiation and in response to an inflammatory stimulus. In both cases, the p38/NF-kB pathway activation leads to the expression of the lipocalin SIP24 and of COX-2. Given the fact that, in the same cells, the COX-2 expression is sustained during the inflammation resolution, at the same time that the SIP24 expression is suppressed, in the present study we tested the hypothesis that COX-2 products play a role in SIP24 repression. Taken together, our results suggest that, during the resolution of inflammation, COX-2 represses the acute phase protein SIP24 and restores physiological conditions, possibly through a pathway involving PPARgamma. Experimental evidences being the following: (1) 15-deoxy-delta 12,14-prostaglandin J(2), but not PGE(2): (i) inhibits the expression of SIP24 in the inflammatory phase and induces COX-2 synthesis; (ii) represses NF-kB activation induced by LPS; (iii) represses the synthesis of microsomal PGE Synthase-1 induced by LPS. (2) PPARgamma and PPARalpha are present in MC615 cells in both proliferating and hyperconfluent cultures. (3) PPARgamma ligand GW7845, but not PPARalpha ligand GW7647: (i) represses the expression of SIP24 induced by LPS; (ii) induces COX-2 expression. (4) p38 is involved in the PPARgamma mediated induction of COX-2. In fact 15-deoxy-delta 12,14-prostaglandin J(2) activates p38 and the cell pretreatment with the p38 specific inhibitor SB203580 represses the expression of COX-2 induced by both the 15-deoxy-delta12,14-prostaglandin J(2) and the PPARgamma ligand GW7845. PMID:18615580

Ulivi, Valentina; Cancedda, Ranieri; Cancedda, Fiorella Descalzi

2008-11-01

308

Single crystal growth and superconductivity of Ca(Fe1-xCox)2As2  

SciTech Connect

We report the single crystal growth of Ca(Fe1-xCox)2As2 (0 <= x <= 0.082) from Sn flux. The temperature-composition phase diagram is mapped out based on the magnetic susceptibility and electrical transport measurements. Phase diagram of Ca(Fe1-xCox)2As2 is qualitatively different from those of Sr and Ba, it could be due to both the charge doping and structural tuning effects associated with Co substitution.

Hu, Rongwei; Ran, Sheng; Budko, Serguei; Straszheim, Warren E.; Canfield, Paul C.

2012-05-18

309

Selective non zinc binding inhibitors of MMP13.  

PubMed

Directed screening has identified a novel series of MMP13 inhibitors that possess good levels of activity whilst possessing excellent selectivity over related MMPs. The binding mode of the series has been solved by co-crystallisation and demonstrates an interesting mode of inhibition without interaction with the catalytic zinc atom. PMID:21669521

De Savi, Chris; Morley, Andrew D; Ting, Attilla; Nash, Ian; Karabelas, Kostas; Wood, Christine M; James, Michael; Norris, Stephen J; Karoutchi, Galith; Rankine, Neil; Hamlin, Gordon; Macfaul, Philip A; Ryan, David; Baker, Sarah V; Hargreaves, David; Gerhardt, Stefan

2011-07-15

310

Selective serotonin reuptake inhibitors: measurement of effect on platelet function  

Microsoft Academic Search

Selective serotonin reuptake inhibitors (SSRIs) reduce platelet serotonin and are associated with increased gastrointestinal bleeding, an effect that is enhanced when taken with NSAIDs or aspirin. The best method to evaluate hemorrhagic events in patients taking SSRIs has not been determined. Platelet aggregation, which is not widely available, shows SSRI inhibition of platelet function; we tested whether a platelet function

DONNA JO MCCLOSKEY; TEODOR T. POSTOLACHE; BERNARD J. VITTONE; KHANH L. NGHIEM; JUDE L. MONSALE; ROBERT A. WESLEY; MARGARET E. RICK

311

Metabolism and Pharmacokinetics of Selective Serotonin Reuptake Inhibitors  

Microsoft Academic Search

1. Five drugs with the predominant pharmacologic effect of inhibiting the neuronal reuptake of serotonin are available worldwide for clinical use. This class of psychoactive drugs, known as selective serotonin reuptake inhibitors (SSRIs), is comprised of fluoxetine, sertraline, paroxetine, fluvoxamine, and citalopram.

C. Lindsay DeVane

1999-01-01

312

Safety of Selective Serotonin Reuptake Inhibitors in Pregnancy  

Microsoft Academic Search

Psychiatric treatment with selective serotonin reuptake inhibitors (SSRIs) may be desirable or necessary during pregnancy; however, the benefit of these treatments must balance the benefits to the mother with any risk to the developing foetus. At the present time, the role of serotonin in normal central nervous system development, as well as the effects of altering serotonin transmission at critical

Carlos D. las Cuevas; Emilio J. Sanz

2006-01-01

313

Novel selective inhibitors of aminopeptidases that generate antigenic peptides.  

PubMed

Endoplasmic reticulum aminopeptidases, ERAP1 and ERAP2, as well as Insulin regulated aminopeptidase (IRAP) play key roles in antigen processing, and have recently emerged as biologically important targets for manipulation of antigen presentation. Taking advantage of the available structural and substrate-selectivity data for these enzymes, we have rationally designed a new series of inhibitors that display low micromolar activity. The selectivity profile for these three highly homologous aminopeptidases provides a promising avenue for modulating intracellular antigen processing. PMID:23916253

Papakyriakou, Athanasios; Zervoudi, Efthalia; Theodorakis, Emmanuel A; Saveanu, Loredana; Stratikos, Efstratios; Vourloumis, Dionisios

2013-09-01

314

Design and Synthesis of Selective Inhibitors of Placental Alkaline Phosphatase  

PubMed Central

Placental Alkaline Phosphatase (PLAP) is a tissue-restricted isozyme of the Alkaline Phosphatase (AP) superfamily. PLAP is an oncodevelopmental enzyme expressed during pregnancy and in a variety of human cancers, but its biological function remains unknown. We report here a series of catechol compounds with great affinity for the PLAP isozyme and significant selectivity over other members of the AP superfamily. These selective PLAP inhibitors will provide small molecule probes for the study of the pathophysiological role of PLAP.

Lanier, Marion; Sergienko, Eduard; Simao, Ana Maria; Su, Ying; Chung, Thomas; Millan, Jose Luis; Cashman, John R.

2010-01-01

315

?9-THC-caused synaptic and memory impairments are mediated through COX-2 signaling.  

PubMed

Marijuana has been used for thousands of years as a treatment for medical conditions. However, untoward side effects limit its medical value. Here, we show that synaptic and cognitive impairments following repeated exposure to ?(9)-tetrahydrocannabinol (?(9)-THC) are associated with the induction of cyclooxygenase-2 (COX-2), an inducible enzyme that converts arachidonic acid to prostanoids in the brain. COX-2 induction by ?(9)-THC is mediated via CB1 receptor-coupled G protein ?? subunits. Pharmacological or genetic inhibition of COX-2 blocks downregulation and internalization of glutamate receptor subunits and alterations of the dendritic spine density of hippocampal neurons induced by repeated ?(9)-THC exposures. Ablation of COX-2 also eliminates ?(9)-THC-impaired hippocampal long-term synaptic plasticity, working, and fear memories. Importantly, the beneficial effects of decreasing ?-amyloid plaques and neurodegeneration by ?(9)-THC in Alzheimer's disease animals are retained in the presence of COX-2 inhibition. These results suggest that the applicability of medical marijuana would be broadened by concurrent inhibition of COX-2. PMID:24267894

Chen, Rongqing; Zhang, Jian; Fan, Ni; Teng, Zhao-Qian; Wu, Yan; Yang, Hongwei; Tang, Ya-Ping; Sun, Hao; Song, Yunping; Chen, Chu

2013-11-21

316

Expression of COX-2 and bcl-2 in oral lichen planus lesions and lichenoid reactions  

PubMed Central

Oral lichen planus and lichenoid reactions are autoimmune type inflammatory conditions of the oral mucosa with similar clinical and histological characteristics. Recent data suggest that oral lichenoid reactions (OLR) present a greater percentage of malignant transformation than oral lichen planus (OLP). Objective To compare the expression of bcl-2 and COX-2 in OLP and OLR. Methods The study population consisted of 65 cases; 34 cases diagnosed as OLR and 31 as OLP. A retrospective study was done, and bcl-2 and COX-2 expression was semiquantitatively analysed. Results Fifty-three per cent (18/34) of the ORL samples tested positive for COX-2, whereas in the OLP group, 81% of the samples (25/31) immunostained positive for COX-2. The Fisher’s exact test for the expression of COX-2 revealed that there are significant differences between the two groups, P = 0.035. With respect to the expression of the bcl-2 protein, 76% (26/34) of the samples were positive in OLR, while 97% (30/31) were positive in the group with OLP. The Fisher’s exact test for the expression of bcl-2 revealed that there are significant statistical differences between the two groups, P = 0.028. Conclusions The expression of bcl-2 and COX-2 was more commonly expressed in OLP when compared with OLR.

Arreaza, Alven J; Rivera, Helen; Correnti, Maria

2014-01-01

317

Quercetin inhibits IL-1?-induced proliferation and production of MMPs, COX-2, and PGE2 by rheumatoid synovial fibroblast.  

PubMed

This study was aimed to determine the effects of quercetin on the interleukin-1? (IL-1?)-induced proliferation of rheumatoid synovial fibroblasts (RASFs) and production of matrix metalloproteinases (MMPs), cyclooxygenase (COX), and prostaglandin E2 (PGE2) by RASFs. The proliferation and apoptosis of RASFs was evaluated with CCK-8 reagent and flow cytometry in the presence of IL-1with CCK-8 reagquercetin. The expression of MMPs, IL-1? enhanced the expression of MMP-1, MMP-3, tissue inhibitor of metalloproteinase (TIMP)-1, COXs, PGE2, and intracellular mitogen-activated protein kinase (MAPK) signalings including phosphorylated extracellular signal-regulated kinase (p-ERK), p-p38, phosphorylated c-Jun N-terminal kinase (p-JNK), and nuclear factor kB (NF-kB) were examined by immunoblotting or semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) in conditions as described above. Quercetin inhibits unstimulated and IL-1?-induced proliferation of RASFs and MMP-1, 3, COX-2 messenger ribonucleic acid and protein expression, PGE2 production induced with IL-1?. Quercetin also inhibits the phosphorylation of ERK-1/2, p38, JNK and activation of NF-kB by IL-1ed. These results indicate that quercetin inhibits synovial fibroblasts proliferation and MMPs, COX-2, and PGE2 production, which involved joint destruction in rheumatoid arthritis (RA), and suggest that it might be a new therapeutic agent for management of RA. PMID:22592909

Sung, Myung-Soon; Lee, Eun-Gyeong; Jeon, Hyun-Soon; Chae, Han-Jung; Park, Seoung Ju; Lee, Yong Chul; Yoo, Wan-Hee

2012-08-01

318

Molecular dynamics simulations for selection of kinetic hydrate inhibitors.  

PubMed

Natural gas hydrates are ice-like structures composed of water and gas molecules that have long been a problem in petroleum industry. Heavy cost of alcohol and glycol injection has spurred an interest in called 'kinetic inhibitors' able to slow down the hydrate formation rather than prevent it. Since it is not possible to compare directly the macroscopic effects of different inhibitors on the kinetics of hydrate formation in computer experiments, a scheme capable of culling the list of candidates for experimental testing was proposed earlier [B. Kvamme, G. Huseby, O.K. Førrisdahl, Molecular dynamics simulations of PVP kinetic inhibitor in liquid water and hydrate/liquid water systems, Mol. Phys. 90 (1997) 979-991]. Molecular dynamics simulations were implemented to test several kinetic inhibitors in a multiphase water-hydrate system with rigid hydrate interface. In addition, a long-scale run was implemented for a system where the hydrate was free to melt and reform. Our conclusion that PVCap will outperform PVP as a kinetic hydrate inhibitor is supported by experimental data. We demonstrate that numerical experiments can be a valuable tool for selecting kinetic inhibitors as well as provide insight into mechanisms of kinetic inhibition and hydrate melting and reformation. PMID:15908248

Kvamme, Bjørn; Kuznetsova, Tatyana; Aasoldsen, Kjetil

2005-06-01

319

Lead identification of novel and selective TYK2 inhibitors.  

PubMed

A therapeutic rationale is proposed for the treatment of inflammatory diseases, such as psoriasis and inflammatory bowel diseases (IBD), by selective targeting of TYK2. Hit triage, following a high-throughput screen for TYK2 inhibitors, revealed pyridine 1 as a promising starting point for lead identification. Initial expansion of 3 separate regions of the molecule led to eventual identification of cyclopropyl amide 46, a potent lead analog with good kinase selectivity, physicochemical properties, and pharmacokinetic profile. Analysis of the binding modes of the series in TYK2 and JAK2 crystal structures revealed key interactions leading to good TYK2 potency and design options for future optimization of selectivity. PMID:23867602

Liang, Jun; Tsui, Vickie; Van Abbema, Anne; Bao, Liang; Barrett, Kathy; Beresini, Maureen; Berezhkovskiy, Leo; Blair, Wade S; Chang, Christine; Driscoll, James; Eigenbrot, Charles; Ghilardi, Nico; Gibbons, Paul; Halladay, Jason; Johnson, Adam; Kohli, Pawan Bir; Lai, Yingjie; Liimatta, Marya; Mantik, Priscilla; Menghrajani, Kapil; Murray, Jeremy; Sambrone, Amy; Xiao, Yisong; Shia, Steven; Shin, Young; Smith, Jan; Sohn, Sue; Stanley, Mark; Ultsch, Mark; Zhang, Birong; Wu, Lawren C; Magnuson, Steven

2013-09-01

320

Aromatase and COX in Breast Cancer: Enzyme inhibitors and beyond  

PubMed Central

Aromatase expression and enzyme activity in breast cancer patients is greater in or near the tumor tissue compared with the normal breast tissue. Complex regulation of aromatase expression in human tissues involves alternative promoter sites that provide tissue-specific control. Previous studies in our laboratories suggested a strong association between aromatase (CYP19) gene expression and the expression of cyclooxygenase (COX) genes. Additionally, nonsteroidal anti-inflammatory drugs (NSAIDs) and COX selective inhibitors can suppress CYP19 gene expression and decrease aromatase activity. Our current hypothesis is that pharmacological regulation of aromatase and/or cyclooxygenases can act locally to decrease the biosynthesis of estrogen and may provide additional therapy options for patients with hormone-dependent breast cancer. Two pharmacological approaches are being developed, one involving mRNA silencing by selective siRNA molecules and the second utilizing small molecule drug design. In the first approach, short interfering RNAs (siRNA) were designed against either human aromatase mRNA or human COX-2 mRNA. Treatment of breast cancer cells with siAROMs completely masked the aromatase enzyme activity. Treatment with COX-2 siRNAs decreased the expression of COX-2 mRNA; furthermore, the siCOX-2-mediated decrease also resulted in suppression of CYP19 mRNA. The small molecule drug design approach focuses on the synthesis and biological evaluation of a novel series of sulfonanilide analogs derived from the COX-2 selective inhibitors. The compounds suppress aromatase enzyme activity in SK-BR-3 breast cancer cells in a dose and time dependent manner, and structure activity analysis does not find a correlation between aromatase suppression and COX inhibition. Real-time PCR analysis demonstrates that the sulfonanilide analogs decrease aromatase gene transcription in breast cells. Thus, these results suggest that the siRNAs and novel sulfonanilides targeting aromatase expression may be valuable tools for selective regulation of aromatase in breast cancer.

Brueggemeier, Robert W.; Su, Bin; Sugimoto, Yasuro; Diaz-Cruz, Edgar S.; Davis, Danyetta D.

2009-01-01

321

Structural origin of selectivity in class II-selective histone deacetylase inhibitors.  

PubMed

The development of class- and isoform-selective histone deacetylase (HDAC) inhibitors is highly desirable for the study of the complex interactions of these proteins central to transcription regulation as well as for the development of selective HDAC inhibitors as drugs in epigenetics. To provide a structural basis for the rational design of such inhibitors, a combined computational and experimental study of inhibition of three different histone deacetylase isoforms, HDAC1, -6, and -8, with three different hydroxamate inhibitors is reported. While SAHA was found to be unselective for the inhibition of class I and class II HDACs, the other inhibitors were found to be selective toward class II HDACs. Molecular dynamics simulations indicate that this selectivity is caused by both the overall shape of the protein surface leading to the active site and specific interactions of an aspartate residue in a polar loop and two phenylalanines and a methionine in a nonpolar loop. Monitoring the specific interactions as a function of the simulation time identifies a key sulfur-pi interaction. The implications of the structural motifs for the design of class II-selective HDAC inhibitors are discussed. PMID:18412327

Estiu, Guillermina; Greenberg, Edward; Harrison, Christopher B; Kwiatkowski, Nicholas P; Mazitschek, Ralph; Bradner, James E; Wiest, Olaf

2008-05-22

322

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

PubMed Central

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 deserves further investigation.

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

323

Exposure to cyclooxygenase-2 inhibitors and risk of cancer: nested case-control studies  

PubMed Central

Background: Selective cyclooxygenase-2 (COX2) inhibitors are widely used as analgesics and it is unclear whether its long-term use affects cancer risk. Methods: A series of nested case–control studies using the QResearch primary care database. Associations of COX2 inhibitor use with risk of all cancers and 10 common site-specific cancers were estimated using conditional logistic regression adjusted for comorbidities, smoking status, socioeconomic status, and use of non-steroidal anti-inflammatory drugs, aspirin and statins. Results: A total of 88?125 cancers, diagnosed between 1998 and 2008, matched with up to five controls, were analysed. Use of COX2 inhibitors for more than a year was associated with a significantly increased risk of breast cancer (odds ratio (OR) 1.24, 95% confidence interval (CI) 1.08–1.42) and haematological malignancies (OR 1.38, 95% CI 1.12–1.69) and a decreased risk of colorectal cancer (OR 0.76, 95% CI 0.63–0.92). There were no other significant associations. Conclusion: Prolonged use of COX2 inhibitors was associated with an increased risk of breast and haematological cancers and decreased risk of colorectal cancer. These findings need to be confirmed using other data sources.

Vinogradova, Y; Coupland, C; Hippisley-Cox, J

2011-01-01

324

Discovery of Selective Menaquinone Biosynthesis Inhibitors against Mycobacterium tuberculosis  

PubMed Central

Aurachin RE (1) is a strong antibiotic that was recently found to possess MenA (1,4-dihydroxy-2-naphthoate prenyltransferase) and bacterial electron transport inhibitory activities. Aurachin RE is the only molecule in a series of aurachin natural products that has the chiral center in the alkyl side chain at C9?-position. To identify selective MenA inhibitors against Mycobacterium tuberculosis, a series of chiral molecules were designed based on the structures of previously identified MenA inhibitors and 1. The synthesized molecules were evaluated in in vitro assays including MenA enzyme and bacterial growth inhibitory assays. We could identify novel MenA inhibitors that showed significant increase in potency of killing non-replicating M. tuberculosis in the low oxygen recovery assay (LORA) without inhibiting other Gram-positive bacterial growth even at high concentrations. The MenA inhibitors reported here are useful new pharmacophores for the development of selective antimycobacterial agents with strong activity against non-replicating M. tuberculosis.

Debnath, Joy; Siricilla, Shajila; Wan, Bajoie; Crick, Dean C.; Lenaerts, Anne J.; Franzblau, Scott G.; Kurosu, Michio

2012-01-01

325

Discovery of potent and selective pyrazolopyrimidine janus kinase 2 inhibitors.  

PubMed

The discovery of somatic Jak2 mutations in patients with chronic myeloproliferative neoplasms has led to significant interest in discovering selective Jak2 inhibitors for use in treating these disorders. A high-throughput screening effort identified the pyrazolo[1,5-a]pyrimidine scaffold as a potent inhibitor of Jak2. Optimization of lead compounds 7a-b and 8 in this chemical series for activity against Jak2, selectivity against other Jak family kinases, and good in vivo pharmacokinetic properties led to the discovery of 7j. In a SET2 xenograft model that is dependent on Jak2 for growth, 7j demonstrated a time-dependent knock-down of pSTAT5, a downstream target of Jak2. PMID:23061660

Hanan, Emily J; van Abbema, Anne; Barrett, Kathy; Blair, Wade S; Blaney, Jeff; Chang, Christine; Eigenbrot, Charles; Flynn, Sean; Gibbons, Paul; Hurley, Christopher A; Kenny, Jane R; Kulagowski, Janusz; Lee, Leslie; Magnuson, Steven R; Morris, Claire; Murray, Jeremy; Pastor, Richard M; Rawson, Tom; Siu, Michael; Ultsch, Mark; Zhou, Aihe; Sampath, Deepak; Lyssikatos, Joseph P

2012-11-26

326

2-Chlorohexadecanal and 2-chlorohexadecanoic acid induce COX-2 expression in human coronary artery endothelial cells.  

PubMed

2-Chlorohexadecanal (2-ClHDA), a 16-carbon chain chlorinated fatty aldehyde that is produced by reactive chlorinating species attack of plasmalogens, is elevated in atherosclerotic plaques, infarcted myocardium, and activated leukocytes. We tested the hypothesis that 2-ClHDA and its metabolites, 2-chlorohexadecanoic acid (2-ClHA) and 2-chlorohexadecanol (2-ClHOH), induce COX-2 expression in human coronary artery endothelial cells (HCAEC). COX-2 protein expression increased in response to 2-ClHDA treatments at 8 and 20 h. 2-ClHA also increased COX-2 expression following an 8 h treatment. Quantitative PCR showed that 2-ClHDA treatment increased COX-2 mRNA over 8 h, while 2-ClHA treatment led to a modest increase by 1 h and those levels remained constant over 8 h. 2-ClHDA led to a significant increase in 6-keto-PGF(1alpha) release (a measure of PGI(2) release) by HCAEC. These data suggest that 2-ClHDA and its metabolite 2-ClHA, which are produced during leukocyte activation, may alter vascular endothelial cell function by upregulation of COX-2 expression. PMID:18493808

Messner, Maria C; Albert, Carolyn J; Ford, David A

2008-07-01

327

Novel Selective Quinazoline Inhibitors of Endothelin Converting Enzyme1  

Microsoft Academic Search

PD 069185 is a highly selective and structurally novel inhibitor of endothelin converting enzyme-1 (ECE-1). PD 069185 is a trisubstituted quinazoline with an IC50value of 0.9 ± 0.1 ?M for inhibition of human ECE-1 from the solubilized membrane fraction of CHO cells stably transfected with human ECE-1 cDNA. Kinetic analysis revealed that PD 069185 is best fit with a competitive

Kyunghye Ahn; Andre M. Sisneros; Sarah B. Herman; Sharon M. Pan; Donald Hupe; Chitase Lee; Sham Nikam; Xue-Min Cheng; Annette M. Doherty; Richard L. Schroeder; Stephen J. Haleen; Semiko Kaw; Noriaki Emoto; Masashi Yanagisawa

1998-01-01

328

Potent, selective pyrimidinetrione-based inhibitors of MMP-13.  

PubMed

Using SAR from two related series of pyrimidinetrione-based inhibitors, compounds with potent MMP-13 inhibition and >100-fold selectivity against other MMPs have been identified. Despite high molecular weights, clogPs, and polar surface areas, the compounds are generally well absorbed and have excellent pharmacokinetic (PK) properties when dosed as sodium salts. In a rat fibrosis model, a compound from the series displayed no fibrosis at exposures many fold greater than its MMP-13 IC50. PMID:16942871

Reiter, Lawrence A; Freeman-Cook, Kevin D; Jones, Christopher S; Martinelli, Gary J; Antipas, Amy S; Berliner, Martin A; Datta, Kaushik; Downs, James T; Eskra, James D; Forman, Michael D; Greer, Elaine M; Guzman, Roberto; Hardink, Joel R; Janat, Fouad; Keene, Nandell F; Laird, Ellen R; Liras, Jennifer L; Lopresti-Morrow, Lori L; Mitchell, Peter G; Pandit, Jayvardhan; Robertson, Donald; Sperger, Diana; Vaughn-Bowser, Marcie L; Waller, Darra M; Yocum, Sue A

2006-11-15

329

Bridged tetrahydroisoquinolines as selective NADPH oxidase 2 (Nox2) inhibitors  

PubMed Central

(1SR,4RS)-3,3-Dimethyl-1,2,3,4-tetrahydro-1,4-(epiminomethano)naphthalenes were synthesized in 2-3 steps from commercially available materials and assessed for specificity and effectiveness across a range of Nox isoforms. The N-pentyl and N-methylenethiophene substituted analogs 11g and 11h emerged as selective Nox2 inhibitors with cellular IC50 values of 20 and 32 ?M, respectively.

Cifuentes-Pagano, Eugenia; Saha, Jaideep; Csanyi, Gabor; Ghouleh, Imad Al; Sahoo, Sanghamitra; Rodriguez, Andres; Wipf, Peter; Pagano, Patrick J.; Skoda, Erin M.

2013-01-01

330

Structure-based discovery of highly selective phosphodiesterase-9A inhibitors and implications for inhibitor design.  

PubMed

A new series of phosphodiesterase-9 (PDE9) inhibitors that contain a scaffold of 6-amino-pyrazolopyrimidinone have been discovered by a combination of structure-based design and computational docking. This procedure significantly saved the load of chemical synthesis and is an effective method for the discovery of inhibitors. The best compound 28 has an IC(50) of 21 nM and 3.3 ?M, respectively, for PDE9 and PDE5 and about 3 orders of magnitude of selectivity against other PDE families. The crystal structure of the PDE9 catalytic domain in complex with 28 has been determined and shows a hydrogen bond between 28 and Tyr424. This hydrogen bond may account for the 860-fold selectivity of 28 against PDE1B, in comparison with about 30-fold selectivity of BAY73-6691. Thus, our studies suggest that Tyr424, a unique residue of PDE8 and PDE9, is a potential target for improvement of selectivity of PDE9 inhibitors. PMID:22985069

Meng, Fei; Hou, Jing; Shao, Yong-Xian; Wu, Pei-Ying; Huang, Manna; Zhu, Xinhai; Cai, Yonghong; Li, Zhe; Xu, Jie; Liu, Peiqing; Luo, Hai-Bin; Wan, Yiqian; Ke, Hengming

2012-10-11

331

Structure-based discovery of highly selective phosphodiesterase-9A inhibitors and implications for inhibitor design  

PubMed Central

A new series of phosphodiesterase-9 (PDE9) inhibitors that contain a scaffold of 6-amino-pyrazolopyrimidinone have been discovered by a combination of structure-based design and computational docking. This procedure significantly saved load of chemical synthesis and is an effective method for the discovery of inhibitors. The best compound 28 has an IC50 of 21 nM and 3.3 µM respectively for PDE9 and PDE5, and about three orders of magnitude of selectivity against other PDE families. The crystal structure of the PDE9 catalytic domain in complex with 28 has been determined and shows a hydrogen bond between 28 and Tyr424. This hydrogen bond may account for the 860-fold selectivity of 28 against PDE1B, in comparison with about 30-fold selectivity of BAY73-6691. Thus, our studies suggest that Tyr424, a unique residue of PDE8 and PDE9, is a potential target for improvement of selectivity of PDE9 inhibitors.

Meng, Fei; Hou, Jing; Shao, Yong-Xian; Wu, Pei-Ying; Huang, Manna; Zhu, Xinhai; Cai, Yonghong; Li, Zhe; Xu, Jie; Liu, Peiqing; Luo, Hai-Bin; Wan, Yiqian; Ke, Hengming

2012-01-01

332

Pharmacological characterization of selective serotonin reuptake inhibitors (SSRIs).  

PubMed

Established antidepressants including tricyclic antidepressants (TCAs), tetracyclic antidepressants and monoamine oxidase inhibitors (MAOIs) affect a series of neurotransmitter functions. In the debate of clinical efficacy much attention has focused on the uptake of noradrenaline (NA) and serotonin (5-HT) as a means to increase neuronal activity. Most antidepressants, whether classic or new, inhibit the uptake of either one or the other or both transmitters. Besides that, all of the classical antidepressants potently inhibit a series of neurotransmitter receptors. A series of newer antidepressants preferentially increase 5-HT transmission by inhibiting 5-HT uptake. Selective serotonin reuptake inhibitors (SSRIs) are those which preferably inhibit 5-HT uptake compared with NA, and which at the same time have no or only slight effect on other uptake mechanisms, neurotransmitter receptors, enzymes, etc. Five SSRIs are currently marked, i.e. citalopram, fluoxetine, fluvoxamine, paroxetine and sertraline. They all fulfil the above-mentioned criteria. Citalopram is the most selective 5-HT-uptake inhibitor, whereas paroxetine is the most potent. By and large the rank order of selectivity is equal in in vitro studies, in biochemical in vivo studies and in behavioural studies. Selectivity and potency for 5-HT uptake do not coincide. The selectivity of SSRIs is also founded on the lack of inhibition of receptors for different neurotransmitters, e.g. acetylcholine, histamine, NA, 5-HT or dopamine (DA), as well as monoamine oxidase (MAO). Citalopram, fluoxetine and sertraline are metabolized to compounds possessing similar properties as the parent drugs, whereas this is not the case with the metabolites of fluvoxamine and paroxetine. Upon repeated administration SSRIs maintain the selective and potent inhibition of 5-HT uptake.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8021435

Hyttel, J

1994-03-01

333

Selective Visualization of Cyclooxygenase-2 in Inflammation and Cancer by Targeted Fluorescent Imaging Agents†  

PubMed Central

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.

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

334

COX-2 Inhibition Potentiates Antiangiogenic Cancer Therapy and Prevents Metastasis in Preclinical Models.  

PubMed

Antiangiogenic agents that block vascular endothelial growth factor (VEGF) signaling are important components of current cancer treatment modalities but are limited by alternative ill-defined angiogenesis mechanisms that allow persistent tumor vascularization in the face of continued VEGF pathway blockade. We identified prostaglandin E2 (PGE2) as a soluble tumor-derived angiogenic factor associated with VEGF-independent angiogenesis. PGE2 production in preclinical breast and colon cancer models was tightly controlled by cyclooxygenase-2 (COX-2) expression, and COX-2 inhibition augmented VEGF pathway blockade to suppress angiogenesis and tumor growth, prevent metastasis, and increase overall survival. These results demonstrate the importance of the COX-2/PGE2 pathway in mediating resistance to VEGF pathway blockade and could aid in the rapid development of more efficacious anticancer therapies. PMID:24964992

Xu, Lihong; Stevens, Janine; Hilton, Mary Beth; Seaman, Steven; Conrads, Thomas P; Veenstra, Timothy D; Logsdon, Daniel; Morris, Holly; Swing, Deborah A; Patel, Nimit L; Kalen, Joseph; Haines, Diana C; Zudaire, Enrique; St Croix, Brad

2014-06-25

335

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

PubMed

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. PMID:24569980

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

2014-03-01

336

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

PubMed

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. PMID:16892341

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

337

Identification of an Adamantyl Azaquinolone JNK Selective Inhibitor  

PubMed Central

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-? challenge models.

2012-01-01

338

Enrichment of Echinacea angustifolia with Bauer alkylamide 11 and Bauer ketone 23 increased anti-inflammatory potential through interference with cox-2 enzyme activity.  

PubMed

Bauer alkylamide 11 and Bauer ketone 23 were previously found to be partially responsible for Echinacea angustifolia anti-inflammatory properties. This study further tested their importance using the inhibition of prostaglandin E(2) (PGE(2)) and nitric oxide (NO) production by RAW264.7 mouse macrophages in the absence and presence of lipopolysaccharide (LPS) and E. angustifolia extracts, phytochemical enriched fractions, or pure synthesized standards. Molecular targets were probed using microarray, qRT-PCR, Western blot, and enzyme assays. Fractions with these phytochemicals were more potent inhibitors of LPS-induced PGE(2) production than E. angustifolia extracts. Microarray did not detect changes in transcripts with phytochemical treatments; however, qRT-PCR showed a decrease in TNF-alpha and an increase of iNOS transcripts. LPS-induced COX-2 protein was increased by an E. angustifolia fraction containing Bauer ketone 23 and by pure phytochemical. COX-2 activity was decreased with all treatments. The phytochemical inhibition of PGE(2) production by Echinacea may be due to the direct targeting of COX-2 enzyme. PMID:20681645

Lalone, Carlie A; Huang, Nan; Rizshsky, Ludmila; Yum, Man-Yu; Singh, Navrozedeep; Hauck, Cathy; Nikolau, Basil J; Wurtele, Eve S; Kohut, Marian L; Murphy, Patricia A; Birt, Diane F

2010-08-11

339

Enrichment of Echinacea angustifolia with Bauer alkylamide 11 and Bauer ketone 23 increased anti-inflammatory potential through interfering with COX-2 enzyme activity  

PubMed Central

Bauer alkylamide 11 and ketone 23 were partially responsible for Echinacea angustifolia anti-inflammatory properties previously. This study further tested their importance using the inhibition of prostaglandin E2 (PGE2) and nitric oxide (NO) production by RAW264.7 mouse macrophages in the absence and presence of lipopolysaccharide (LPS) and E. angustifolia extracts, phytochemical enriched fractions, or pure synthesized standards. Molecular targets were probed using microarray, qRT-PCR, western blot, and enzyme assays. Fractions with these phytochemicals were more potent inhibitors of LPS induced PGE2 production than E. angustifolia extracts. Microarray did not detect changes in transcripts with phytochemical treatments; however qRT-PCR showed decrease in TNF-? and increase of iNOS transcripts. LPS induced COX-2 protein was increased by an E. angustifolia fraction containing Bauer ketone 23 and by pure phytochemical. COX-2 activity was decreased with all treatments. The phytochemical inhibition of PGE2 production by Echinacea may be due to the direct targeting of COX-2 enzyme.

LaLone, Carlie A.; Huang, Nan; Rizshsky, Ludmila; Yum, Man-Yu; Singh, Navrozedeep; Hauck, Cathy; Nikolau, Basil J.; Wurtele, Eve S.; Kohut, Marian L.; Murphy, Patricia A.; Birt, Diane F.

2013-01-01

340

Antinociceptive Effect of Tetrandrine on LPS-Induced Hyperalgesia via the Inhibition of IKK? Phosphorylation and the COX-2/PGE2 Pathway in Mice  

PubMed Central

Tetrandrine (TET) is a bisbenzylisoquinoline alkaloid that is isolated from the Stephania Tetrandra. It is known to possess anti-inflammatory and immunomodulatory effects. We have shown that TET can effectively suppress the production of bacterial lipopolysaccharide (LPS)-induced inflammatory mediators, including cyclooxygenases (COXs), in macrophages. However, whether TET has an antinociceptive effect on LPS-induced hyperalgesia is unknown. In the present study, we investigated the potential antinociceptive effects of TET and the mechanisms by which it elicits its effects on LPS-induced hyperalgesia. LPS effectively evoked hyperalgesia and induced the production of PGE2 in the sera, brain tissues, and cultured astroglia. TET pretreatment attenuated all of these effects. LPS also activated inhibitor of ?B (I?B) kinase ? (IKK?) and its downstream components in the I?B/nuclear factor (NF)-?B signaling pathway, including COX-2; the increase in expression levels of these components was significantly abolished by TET. Furthermore, in primary astroglia, knockdown of IKK?, but not IKK?, reversed the effects of TET on the LPS-induced increase in I?B phosphorylation, P65 phosphorylation, and COX-2. Our results suggest that TET can effectively exert antinociceptive effects on LPS-induced hyperalgesia in mice by inhibiting IKK? phosphorylation, which leads to the reduction in the production of important pain mediators, such as PGE2 and COX-2, via the IKK?/I?B/NF-?B pathway.

Zhao, Hengguang; Luo, Fuling; Li, Hongzhong; Zhang, Li; Yi, Yongfen; Wan, Jingyuan

2014-01-01

341

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

Microsoft Academic Search

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

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

2003-01-01

342

Selective HDAC1/HDAC2 Inhibitors Induce Neuroblastoma Differentiation  

PubMed Central

Summary While cytotoxic chemotherapy remains the hallmark of cancer treatment, intensive regimens fall short in many malignancies, including high-risk neuroblastoma. One alternative strategy is to therapeutically promote tumor differentiation. We created a gene expression signature to measure neuroblast maturation, adapted it to a high-throughput platform, and screened a diversity oriented synthesis-generated small-molecule library for differentiation inducers. We identified BRD8430, containing a nine-membered lactam, an ortho-amino anilide functionality, and three chiral centers, as a selective Class I histone deacetylase (HDAC) inhibitor (HDAC1>2>3). Further investigation demonstrated that selective HDAC1/HDAC2 inhibition using compounds or RNA interference induced differentiation and decreased viability in neuroblastoma cell lines. Combined treatment with 13-cis retinoic acid augmented these effects and enhanced activation of retinoic acid signaling. Therefore, by applying a chemical genomic screening approach we identified selective HDAC1/HDAC2 inhibition as a strategy to induce neuroblastoma differentiation.

Frumm, Stacey M.; Fan, Zi Peng; Ross, Kenneth N.; Duvall, Jeremy R.; Gupta, Supriya; VerPlank, Lynn; Suh, Byung-Chul; Holson, Edward; Wagner, Florence F.; Smith, William B.; Paranal, Ronald M.; Bassil, Christopher F.; Qi, Jun; Roti, Giovanni; Kung, Andrew L.; Bradner, James E.; Tolliday, Nicola; Stegmaier, Kimberly

2013-01-01

343

Curcumin alleviates neuropathic pain by inhibiting p300/CBP histone acetyltransferase activity-regulated expression of BDNF and cox-2 in a rat model.  

PubMed

The management of neuropathic pain is still a major challenge because of its unresponsiveness to most common treatments. Curcumin has been reported to play an active role in the treatment of various neurological disorders, such as neuropathic pain. Curcumin has long been recognized as a p300/CREB-binding protein (CBP) inhibitor of histone acetyltransferase (HAT) activity. However, this mechanism has never been investigated for the treatment of neuropathic pain with curcumin. The aim of the present study was to investigate the anti-nociceptive role of curcumin in the chronic constriction injury (CCI) rat model of neuropathic pain. Furthermore, with this model we investigated the effect of curcumin on P300/CBP HAT activity-regulated release of the pro-nociceptive molecules, brain-derived neurotrophic factor (BDNF) and cyclooxygenase-2 (Cox-2). Treatment with 40 and 60 mg/kg body weight curcumin for 7 consecutive days significantly attenuated CCI-induced thermal hyperalgesia and mechanical allodynia, whereas 20 mg/kg curcumin showed no significant analgesic effect. Chromatin immunoprecipitation analysis revealed that curcumin dose-dependently reduced the recruitment of p300/CBP and acetyl-Histone H3/acetyl-Histone H4 to the promoter of BDNF and Cox-2 genes. A similar dose-dependent decrease of BDNF and Cox-2 in the spinal cord was also observed after curcumin treatment. These results indicated that curcumin exerted a therapeutic role in neuropathic pain by down-regulating p300/CBP HAT activity-mediated gene expression of BDNF and Cox-2. PMID:24603592

Zhu, Xiaoyan; Li, Qian; Chang, Ruimin; Yang, Dong; Song, Zongbing; Guo, Qulian; Huang, Changsheng