Science.gov

Sample records for cyclooxygenase-2 inhibitors non-selective

  1. [Recent development of selective cyclooxygenase-2 inhibitors].

    PubMed

    Kawai, Shinichi

    2002-12-01

    Nonsteroidal anti-inflammatory drugs(NSAIDs) are clinically effective against the inflammatory symptoms of rheumatoid arthritis. Recent attention has been focused on selective cyclooxygenase(COX)-2 inhibitors, a type of NSAID that inhibits a subtype of COX. Because of the different actions of COX-1 and COX-2, selective COX-2 inhibitors were expected to reduce adverse reactions such as gastrointestinal disorders. Various clinical studies have confirmed that the efficacy of COX-2 inhibitors for RA is similar to that of conventional NSAIDs, but they cause fewer severe gastrointestinal disorders. The incidence of complications related to renal dysfunction, such as edema and hypertension, is not different. Patients using selective COX-2 inhibitors have recently been reported to show an increase in thrombotic complications such as myocardial infarction. Therefore, more data on adverse events should be collected in the future from large-scale clinical studies to further clarify the actual value of selective COX-2 inhibitors. PMID:12510364

  2. Renal Effects of Prostaglandins and Cyclooxygenase-2 Inhibitors

    PubMed Central

    2008-01-01

    Prostaglandins (PGs) with best-defined renal functions are PGE2 and prostacyclin (PGI2). These vasodilatory PGs increase renal blood flow and glomerular filtration rate under conditions associated with decreased actual or effective circulating volume, resulting in greater tubular flow and secretion of potassium. Under conditions of decreased renal perfusion, the production of renal PGs serves as an important compensatory mechanism. PGI2 (and possibly PGE2) increases potassium secretion mainly by stimulating secretion of renin and activating the renin-angiotensin system, which leads to increased secretion of aldosterone. In addition, PGE2 is involved in the regulation of sodium and water reabsorption and acts as a counterregulatory factor under conditions of increased sodium reabsorption. PGE2 decreases sodium reabsorption at the thick ascending limb of the loop of Henle probably via inhibition of the Na+-K+-2Cl- cotransporter type 2 (NKCC2). Cyclooxygenase inhibitors may enhance urinary concentrating ability in part through effects to upregulate NKCC2 in the thick ascending limb of Henle's loop and aquaporin-2 in the collecting duct. Thus, they may be useful to treat Bartter's syndrome and nephrogenic diabetes insipidus. PMID:24459520

  3. Inhibition of bacterial multidrug resistance by celecoxib, a cyclooxygenase-2 inhibitor.

    PubMed

    Kalle, Arunasree M; Rizvi, Arshad

    2011-01-01

    Multidrug resistance (MDR) is a major problem in the treatment of infectious diseases and cancer. Accumulating evidence suggests that the cyclooxygenase-2 (COX-2)-specific inhibitor celecoxib would not only inhibit COX-2 but also help in the reversal of drug resistance in cancers by inhibiting the MDR1 efflux pump. Here, we demonstrate that celecoxib increases the sensitivity of bacteria to the antibiotics ampicillin, kanamycin, chloramphenicol, and ciprofloxacin by accumulating the drugs inside the cell, thus reversing MDR in bacteria. PMID:20937780

  4. O-desmethylquinine as a cyclooxygenase-2 (COX-2) inhibitors using AutoDock Vina

    NASA Astrophysics Data System (ADS)

    Damayanti, Sophi; Mahardhika, Andhika Bintang; Ibrahim, Slamet; Chong, Wei Lim; Lee, Vannajan Sanghiran; Tjahjono, Daryono Hadi

    2014-10-01

    Computational approach was employed to evaluate the biological activity of novel cyclooxygenase-2 COX-2 inhibitor, O-desmethylquinine, in comparison to quinine as common inhibitor which can also be used an agent of antipyretic, antimalaria, analgesic and antiinflamation. The molecular models of the compound were constructed and optimized with the density function theory with at the B3LYP/6-31G (d,p) level using Gaussian 09 program. Molecular docking studies of the compounds were done to obtain the COX-2 complex structures and their binding energies were analyzed using the AutoDock Vina. The results of docking of the two ligands were comparable and cannot be differentiated from the energy scoring function with AutoDock Vina.

  5. Inhibitors of cyclooxygenase-2 (COX-2) suppressed the proliferation and differentiation of human leukaemia cell lines.

    PubMed

    Nakanishi, Y; Kamijo, R; Takizawa, K; Hatori, M; Nagumo, M

    2001-08-01

    Prostaglandins (PG) are known to play important roles in the proliferation and differentiation of leukaemia cells. The effect of the inhibitors of cyclooxygenase-2 (COX-2), a rate-limiting enzyme for the synthesis of PG, on the proliferation and differentiation of leukaemia cell lines was investigated. COX-2 inhibitors, NS-398 and nabumetone, suppressed the proliferation of U-937 and ML-1 cells by inducing a G0/G1 cell-cycle arrest. Cell-cycle arrest induced by these COX-2 inhibitors was not associated with an upregulation of the cyclin-dependent kinase inhibitors. COX-2 inhibitors also inhibited the differentiation of these cells induced by interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and retinoic acid (RA). Treatment with NS-398 did not suppress the levels of PGs produced by these cells. Although COX-2 antisense oligonucleotide showed a similar inhibitory effect on these cells, its inhibitory effect was smaller than that of NS-398. These results suggest that COX-2 inhibitors may suppress the proliferation and differentiation of leukaemia cells both via COX-2-dependent and -independent pathways. PMID:11506967

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

    PubMed

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

    2006-08-15

    We report that administration of celecoxib, a specific cyclooxygenase-2 (COX-2) inhibitor, in combination with a dendritic cell-based cancer vaccine significantly augments vaccine efficacy in reducing primary tumor burden, preventing metastasis, and increasing survival. This combination treatment was tested in MMTV-PyV MT mice that develop spontaneous mammary gland tumors with metastasis to the lungs and bone marrow. Improved vaccine potency was associated with an increase in tumor-specific CTLs. Enhanced CTL activity was attributed to a significant decrease in levels of tumor-associated IDO, a negative regulator of T cell activity. We present data suggesting that inhibiting COX-2 activity in vivo regulates IDO expression within the tumor microenvironment; this is further corroborated in the MDA-MB-231 human breast cancer cell line. Thus, a novel mechanism of COX-2-induced immunosuppression via regulation of IDO has emerged that may have implications in designing future cancer vaccines. PMID:16888001

  7. Meloxicam, a cyclooxygenase 2 inhibitor, supports hematopoietic recovery in gamma-irradiated mice.

    PubMed

    Hofer, M; Pospísil, M; Znojil, V; Holá, J; Vacek, A; Weiterová, L; Streitová, D; Kozubík, A

    2006-09-01

    Meloxicam, a selective inhibitor of cyclooxygenase 2, a nonsteroidal anti-inflammatory drug with an improved side-effects profile in terms of gastrointestinal toxicity, has been found to stimulate hematopoiesis in whole-body gamma-irradiated mice. A distinct corroboration of this positive action of meloxicam is an enhancement of the recovery of hematopoietic progenitor cells committed to granulocyte-macrophage and erythroid development, which has been demonstrated in sublethally irradiated animals treated with meloxicam at a dose of 20 mg/kg administered intraperitoneally either singly 1 h before irradiation or repeatedly after radiation exposure. The results suggest that meloxicam can be added to the list of biological response modifiers that can be used in the treatment of hematopoietic damage induced by ionizing radiation. PMID:16953674

  8. Mitigation and Treatment of Radiation-Induced Thoracic Injury With a Cyclooxygenase-2 Inhibitor, Celecoxib

    SciTech Connect

    Hunter, Nancy R.; Valdecanas, David; Liao Zhongxing; Milas, Luka; Thames, Howard D.; Mason, Kathy A.

    2013-02-01

    Purpose: To test whether a cyclooxygenase-2 inhibitor (celecoxib) could reduce mortality resulting from radiation-induced pneumonitis. Methods and Materials: Celecoxib was given to mice twice daily for 40 consecutive days starting on the day of local thoracic irradiation (LTI) or 40 or 80 days later. C3Hf/KamLaw mice were observed for morbidity, and time to death was determined. Results were analyzed using the Cox proportional hazards model. Results: Timing of celecoxib relative to LTI determined efficacy. A significant reduction in time to death was achieved only when celecoxib was started 80 days after LTI, corresponding to the time when pneumonitis is expressed. For these mice the reduction in mortality was quantified as a hazard ratio for mortality of treated vs untreated of 0.36 (95% confidence interval [CI] 0.24-0.53), thus significantly less than 1.0. Correspondingly, the median lethal dose for treated mice (12.9 Gy; 95% CI 12.55-13.25 Gy) was significantly (P=.026) higher than for untreated mice (12.4 Gy; 95% CI 12.2-12.65 Gy). Conclusions: Celecoxib significantly reduced lung toxicity when administered months after LTI when the deleterious effects of radiation were expressed. The schedule-dependent reduction in fatal pneumonitis suggests that celecoxib could be clinically useful by reintroduction of treatment months after completion of radiation therapy. These findings may be important for designing clinical trials using cyclooxygenase-2 inhibitors to treat radiation-induced lung toxicity as a complement to concurrent radiation therapy of lung cancers.

  9. DNA-PKcs-Dependent Modulation of Cellular Radiosensitivity by a Selective Cyclooxygenase-2 Inhibitor

    SciTech Connect

    Kodym, Elisabeth; Kodym, Reinhard; Chen, Benjamin P.; Chen, David J.; Morotomi-Yano, Keiko; Choy, Hak; Saha, Debabrata

    2007-09-01

    Purpose: Inhibition of cyclooxygenase-2 has been shown to increase radiosensitivity. Recently, the suppression of radiation-induced DNA-dependant protein kinase (DNA-PK) activity by the selective cyclooxygenase-2 inhibitor celecoxib was reported. Given the importance of DNA-PK for repair of radiation-induced DNA double-strand breaks by nonhomologous end-joining and the clinical use of the substance, we investigated the relevance of the DNA-PK catalytic subunit (DNA-PKcs) for the modulation of cellular radiosensitivity by celecoxib. Methods and Materials: We used a syngeneic model of Chinese hamster ovarian cell lines: AA8, possessing a wild-type DNK-PKcs; V3, lacking a functional DNA-PKcs; and V3/WT11, V3 stably transfected with the DNA-PKcs. The cells were treated with celecoxib (50 {mu}M) for 24 h before irradiation. The modulation of radiosensitivity was determined using the colony formation assay. Results: Treatment with celecoxib increased the cellular radiosensitivity in the DNA-PKcs-deficient cell line V3 with a dose-enhancement ratio of 1.3 for a surviving fraction of 0.5. In contrast, clonogenic survival was increased in DNA-PKcs wild-type-expressing AA8 cells and in V3 cells transfected with DNA-PKcs (V3/WT11). The decrease in radiosensitivity was comparable to the radiosensitization in V3 cells, with a dose-enhancement ratio of 0.76 (AA8) and 0.80 (V3/WT11) for a survival of 0.5. Conclusions: We have demonstrated a DNA-PKcs-dependent differential modulation of cellular radiosensitivity by celecoxib. These effects might be attributed to alterations in signaling cascades downstream of DNA-PK toward cell survival. These findings offer an explanation for the poor outcomes in some recently published clinical trials.

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

    PubMed Central

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

    2016-01-01

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

  11. The cyclooxygenase-2 selective inhibitor, etodolac, but not aspirin reduces neovascularization in a murine ischemic hind limb model.

    PubMed

    Tanaka, Kohei; Yamamoto, Yasutaka; Tsujimoto, Shunsuke; Uozumi, Naonori; Kita, Yoshihiro; Yoshida, Akio; Shimizu, Takao; Hisatome, Ichiro

    2010-02-10

    Cyclooxygenase inhibitors are often prescribed to relieve severe ischemic leg pain in critical ischemic limb patients. Prescription of high doses of aspirin and selective cyclooxygenase-2 inhibitors is reported to increase cardiovascular events through suppression of the vasodilative prostanoid prostaglandin I(2) in endothelium. Here, we evaluated the influence of aspirin and etodolac, a selective cyclooxygenase-2 inhibitor, on neovascularization using a murine ischemia hind limb model. C57BL/6J mice were treated with aspirin or etodolac for twenty-eight days after induction of ischemia. We exploited a concentration of the agents that suppressed cyclooxygenase activity efficiently, especially in prostaglandin I(2) production. Recovery of limb blood perfusion and capillary density in ischemic limbs was significantly suppressed by etodolac treatment when compared to the aspirin treated group and untreated group. Production of 6-keto prostaglandin F(1alpha) and prostaglandin E(2) was lower in the aspirin treated group when compared with the etodolac-treated group. Also, these concentrations were lower in both treatment groups compared with the untreated group. Immunohistochemical analysis suggested cyclooxygenase-2 was expressed in endothelium but not in inflammatory cells in ischemic tissue from the acute to chronic phase. Cyclooxygenase-1 was expressed strongly in inflammatory cells in the acute phase. Furthermore, bone marrow-derived mononuclear cell transplantation improved neovascularization, whereas aspirin and etodolac did not inhibit these effects. Production of arachidonic acid metabolites by transplanted cells was independent of the improvement of neovascularization. In conclusion, cyclooxygenase-2 inhibition reduces ischemia-induced neovascularization. PMID:19879866

  12. Premedication with cyclooxygenase-2 inhibitor meloxicam reduced postoperative pain in patients after oral surgery.

    PubMed

    Aoki, T; Yamaguchi, H; Naito, H; Shiiki, K; Izawa, K; Ota, Y; Sakamoto, H; Kaneko, A

    2006-07-01

    The efficacy of the selective cyclooxygenase-2 (COX-2) inhibitor meloxicam for treatment of postoperative oral surgical pain was assessed in a randomized controlled trial. Patients undergoing unilateral mandibular 3rd molar extraction surgery were allocated to 3 groups, A, B and C. After oral premedication of meloxicam 10 mg in group A, ampiroxicam 27 mg in group B and placebo in group C, surgery was completed within 30 min under local anaesthesia using 2% lidocaine. For postoperative pain relief the patients were allowed to take oral loxoprofen (60 mg per tablet). Postoperative pain was evaluated at the clinic on the 1st, 7th and 14th postoperative day (POD) using a visual analogue scale (VAS), as was the number of loxoprofen tablets consumed, and the results were compared among the 3 groups with statistical significance of P<0.05. VAS scores on 1 POD were significantly lower in group A than in group C. Loxoprofen consumption on the day of surgery and 1 POD was significantly lower in group A than in group C (P<0.01). Total analgesic consumption was significantly lower in groups A and B than in group C (P<0.02). The COX-2 inhibitor, meloxicam 10 mg used for premedication reduced postoperative pain compared with control in oral surgery. PMID:16540287

  13. Pathogenetic role of cyclooxygenase-2 in hyperprostaglandin E syndrome/antenatal Bartter syndrome: therapeutic use of the cyclooxygenase-2 inhibitor nimesulide.

    PubMed

    Nüsing, R M; Reinalter, S C; Peters, M; Kömhoff, M; Seyberth, H W

    2001-10-01

    Patients with hyperprostaglandin E syndrome/antenatal Bartter syndrome typically have renal salt wasting, hypercalciuria with nephrocalcinosis, and secondary hyperaldosteronism. Antenatally, these patients have fetal polyuria, leading to polyhydramnios and premature birth. Hyperprostaglandin E syndrome/antenatal Bartter syndrome is accompanied by a pathologically elevated synthesis of prostaglandin E(2), thought to be responsible for aggravation of clinical symptoms such as salt and water loss, vomiting, diarrhea, and failure to thrive. In this study administration of the cyclooxygenase-2 (COX-2) specific inhibitor nimesulide to patients with hyperprostaglandin E syndrome/antenatal Bartter syndrome blocked renal prostaglandin E(2) formation and relieved the key parameters hyperprostaglandinuria, secondary hyperaldosteronism, and hypercalciuria. Partial suppression of serum thromboxane B(2) synthesis resulting from platelet COX-1 activity and complete inhibition of urinary 6-keto-prostaglandin F(1alpha), reflecting endothelial COX-2 activity, indicate preferential inhibition of COX-2 by nimesulide. Amelioration of the clinical symptoms by use of nimesulide indicates that COX-2 may play an important pathogenetic role in hyperprostaglandin E syndrome/antenatal Bartter syndrome. Moreover, on the basis of our data we postulate that COX-2-derived prostaglandin E(2) is an important mediator for stimulation of the renin-angiotensin-aldosterone system in the kidney. PMID:11673754

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

    SciTech Connect

    Zuo, Chaohui; Qiu, Xiaoxin; Liu, Nianli; Yang, Darong; Xia, Man; Liu, Jingshi; Wang, Xiaohong; and others

    2015-05-01

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

  15. Cyclooxygenase-2 Inhibitor Reduces Hepatic Stiffness in Pediatric Chronic Liver Disease Patients Following Kasai Portoenterostomy

    PubMed Central

    Chang, Hye Kyung; Chang, Eun Young; Ryu, Seonae

    2016-01-01

    Purpose The purpose of this study was to define the role of cyclooxygenase-2 inhibitors (COX-2i) in reducing hepatic fibrosis in pediatric patients with chronic liver disease. Materials and Methods From September 2009 to September 2010, patients over 2 years old who visited our outpatient clinic for follow-up to manage their chronic liver disease after Kasai portoenterostomy for biliary atresia, were included in this study. Volunteers were assigned to the study or control groups, according to their preference. A COX-2i was given to only the study group after obtaining consent. The degree of hepatic fibrosis (liver stiffness score, LSS) was prospectively measured using FibroScan, and liver function was examined using serum analysis before and after treatment. After 1 year, changes in LSSs and liver function were compared between the two groups. Results Twenty-five patients (18 females and 7 males) were enrolled in the study group. The control group included 44 patients (26 females and 18 males). After 1 year, the least square mean values for the LSSs were significantly decreased by 3.91±0.98 kPa (p=0.004) only in the study group. Serum total bilirubin did not decrease significantly in either group. Conclusion COX-2i treatment improved the LSS in patients with chronic liver disease after Kasai portoenterostomy for biliary atresia. PMID:27189282

  16. Novel effects of the cyclooxygenase-2-selective inhibitor NS-398 on IL-1β-induced cyclooxygenase-2 and IL-8 expression in human ovarian granulosa cells.

    PubMed

    Ou, Hui-Ling; Sun, David; Peng, Yen-Chun; Wu, Yuh-Lin

    2016-08-01

    Ovulation is a critical inflammation-like event that is central to ovarian physiology. IL-1β is an immediate early pro-inflammatory cytokine that regulates production of several other inflammatory mediators, such as cyclooxygenase 2 (COX)-2 and IL-8. NS-398 is a selective inhibitor of COX-2 bioactivity and thus this drug is able to mitigate the COX-2-mediated production of downstream prostaglandins and the subsequent inflammatory response. Here we have investigated the action of NS-398 using a human ovarian granulosa cell line, KGN, by exploring IL-1β-regulated COX-2 and IL-8 expression. First, NS-398, instead of reducing inflammation, appeared to further enhance IL-1β-mediated COX-2 and IL-8 production. Using selective inhibitors targeting various signaling molecules, MAPK and NF-κB pathways both seemed to be involved in the impact of NS-398 on IL-1β-induced COX-2 and IL-8 expression. NS-398 also promoted IL-1β-mediated NF-κB p65 nuclear translocation but had no effect on IL-1β-activated MAPK phosphorylation. Flow cytometry analysis demonstrated that NS-398, in combination with IL-1β, significantly enhanced cell cycle progression involving IL-8. Our findings demonstrate a clear pro-inflammatory function for NS-398 in the IL-1β-mediated inflammatory response of granulosa cells, at least in part, owing to its augmenting effect on the IL-1β-induced activation of NF-κB. PMID:27312705

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

    PubMed Central

    Barozzi, Nadia; Tett, Susan E

    2008-01-01

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

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

    PubMed Central

    2012-01-01

    Background There are limited population-based studies focusing on the chemopreventive effects of selective cyclooxygenase-2 (COX-2) inhibitors against colorectal cancer. The purpose of this study is to assess the trends and dose–response effects of various medication possession ratios (MPR) of selective COX-2 inhibitor used for chemoprevention of colorectal cancer. Methods A population-based case–control study was conducted using the Taiwan Health Insurance Research Database (NHIRD). The study comprised 21,460 colorectal cancer patients and 79,331 controls. The conditional logistic regression was applied to estimate the odds ratios (ORs) for COX-2 inhibitors used for several durations (5 years, 3 years, 1 year, 6 months and 3 months) prior to the index date. Results In patients receiving selective COX-2 inhibitors, the OR was 0.51 (95% CI=0.29~0.90, p=0.021) for an estimated 5-year period in developing colorectal cancer. ORs showing significant protection effects were found in 10% of MPRs for 5-year, 3-year, and 1-year usage. Risk reduction against colorectal cancer by selective COX-2 inhibitors was observed as early as 6 months after usage. Conclusion Our results indicate that selective COX-2 inhibitors may reduce the development of colorectal cancer by at least 10% based on the MPRs evaluated. Given the limited number of clinical reports from general populations, our results add to the knowledge of chemopreventive effects of selective COX-2 inhibitors against cancer in individuals at no increased risk of colorectal cancer. PMID:23217168

  19. Design and synthesis of [(125)I]Pyricoxib: A novel (125)I-labeled cyclooxygenase-2 (COX-2) inhibitors.

    PubMed

    Tietz, Ole; Dzandzi, James; Bhardwaj, Atul; Valliant, John F; Wuest, Frank

    2016-03-15

    Cyclooxygenase-2 (COX-2) is the key enzyme in the prostaglandin synthesis pathway which is involved in various pathophysiological conditions. The enzyme is membrane bound and located inside of the endoplasmic reticulum and nuclear membrane. Effective perfusion of inhibitors to the active site requires lipophilic drugs, which consequently display high unspecific background accumulation, for example, in fatty tissues. The objective of this work was the development of a small molecule radiolabeled with a long-lived iodine radioisotope to enable longer imaging times and better target-to-background ratios. A group of iodinated compounds (8-10) was synthesized and identified as selective COX-2 inhibitors (COX-2 IC50=0.85-13 μM). Molecular docking results provided the theoretical support for the experimental COX-2 inhibition data. Furthermore, a novel (125)I-containing trifluoro-pyrimidine compound ([(125)I]Pyricoxib) was prepared via radioiododestannylation reaction as potent and selective COX-2 inhibitor. Radiosynthesis of [(125)I]Pyricoxib was accomplished with innovative fluorous chemistry using fluorous chloroamine-T (F-CAT) as novel oxidizing agent in high radiochemical yields of 91 ± 4%. PMID:26898334

  20. Cyclooxygenase-2 inhibitors in patients with high gastrointestinal risk: are we there yet?

    PubMed

    Wong, Vincent Wai-Sun; Chan, Francis Ka-Leung

    2009-01-01

    Gastrointestinal complications from the use of nonsteroidal antiinflammatory drugs (NSAIDs) are common and costly. Cyclooxygenase (COX)-2 inhibitors cause fewer gastrointestinal events than nonselective NSAIDs but may still result in peptic ulcer complications in a significant proportion of high-risk patients. The risk can be further reduced by prescribing COX-2 inhibitors together with proton pump inhibitors. Small-bowel injury is also commonly seen in long-term users of COX-2 inhibitors. The potential cardiovascular side effects of most COX-2 inhibitors and NSAIDs pose great challenge to physicians. Further studies are required to optimize the treatment regimen in patients with high cardiovascular and gastrointestinal risk and to decide the best treatment options for patients with small- and large-bowel complications. PMID:19148794

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed Central

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

    2011-01-01

    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. PMID:21340007

  3. Cyclooxygenase-2 inhibitors for non-small-cell lung cancer: A phase II trial and literature review

    PubMed Central

    YOKOUCHI, HIROSHI; KANAZAWA, KENYA; ISHIDA, TAKASHI; OIZUMI, SATOSHI; SHINAGAWA, NAOFUMI; SUKOH, NORIAKI; HARADA, MASAO; OGURA, SHIGEAKI; MUNAKATA, MITSURU; DOSAKA-AKITA, HIROTOSHI; ISOBE, HIROSHI; NISHIMURA, MASAHARU

    2014-01-01

    Several preclinical and clinical studies have demonstrated that cyclooxygenase-2 (COX-2) inhibitors are efficient for the treatment of non-small-cell lung cancer (NSCLC). However, two recent phase III clinical trials using COX-2 inhibitors in combination with platinum-based chemotherapy failed to demonstrate a survival benefit. Thus, validation and discussion regarding the usefulness of COX-2 inhibitors for patients with NSCLC are required. We conducted a prospective trial using COX-2 inhibitors for the treatment of 50 NSCLC patients accrued between April, 2005 and July, 2006. Patients with untreated advanced NSCLC received oral meloxicam (150 mg daily), carboplatin (area under the curve = 5 mg/ml × min on day 1) and docetaxel (60 mg/m2 on day 1) every 3 weeks. The primary endpoint was response rate. The response and disease control rates were 36.0 and 76.0%, respectively. The time-to-progression (TTP) and overall survival (OS) were 5.7 months [95% confidence interval (CI): 4.6–6.7] and 13.7 months (95% CI: 11.4–15.9), respectively. The 1-year survival ratio was 56.0%. Grade 3 neuropathy was observed in only 1 patient. We performed tumor immunohistochemistry for COX-2 and p27 and investigated the correlation between their expression and clinical outcome. COX-2 expression in the tumor tended to correlate with a higher response rate (50.0% in the high- and 18.2% in the low-COX-2 group; P=0.092). Based on our results and previous reports, various trial designs, such as the prospective use of COX-2 inhibitors only for patients with COX-2-positive NSCLC, including the exploratory analysis of biomarkers associated with the COX-2 pathway, may be worth further consideration. PMID:25054040

  4. Cyclooxygenase-2 inhibitor induces apoptosis in breast cancer cells in an in vivo model of spontaneous metastatic breast cancer.

    PubMed

    Basu, Gargi D; Pathangey, Latha B; Tinder, Teresa L; Lagioia, Michelle; Gendler, Sandra J; Mukherjee, Pinku

    2004-11-01

    Cyclooxygenase-2 (COX-2) inhibitors are rapidly emerging as a new generation of therapeutic drug in combination with chemotherapy or radiation therapy for the treatment of cancer. The mechanisms underlying its antitumor effects are not fully understood and more thorough preclinical trials are needed to determine if COX-2 inhibition represents a useful approach for prevention and/or treatment of breast cancer. The purpose of this study was to evaluate the growth inhibitory mechanism of a highly selective COX-2 inhibitor, celecoxib, in an in vivo oncogenic mouse model of spontaneous breast cancer that resembles human disease. The oncogenic mice carry the polyoma middle T antigen driven by the mouse mammary tumor virus promoter and develop primary adenocarcinomas of the breast. Results show that oral administration of celecoxib caused significant reduction in mammary tumor burden associated with increased tumor cell apoptosis and decreased proliferation in vivo. In vivo apoptosis correlated with significant decrease in activation of protein kinase B/Akt, a cell survival signaling kinase, with increased expression of the proapoptotic protein Bax and decreased expression of the antiapoptotic protein Bcl-2. In addition, celecoxib treatment reduced levels of proangiogenic factor (vascular endothelial growth factor), suggesting a role of celecoxib in suppression of angiogenesis in this model. Results from these preclinical studies will form the basis for assessing the feasibility of celecoxib therapy alone or in combination with conventional therapies for treatment and/or prevention of breast cancer. PMID:15561779

  5. Comparison of benefit–risk preferences of patients and physicians regarding cyclooxygenase-2 inhibitors using discrete choice experiments

    PubMed Central

    Byun, Ji-Hye; Kwon, Sun-Hong; Lee, Ji-Eun; Cheon, Ji-Eun; Jang, Eun-Jin; Lee, Eui-Kyung

    2016-01-01

    Purpose To elucidate and compare benefit–risk preferences among Korean patients and physicians concerning cyclooxygenase-2 (Cox-2) inhibitor treatments for arthritis. Materials and methods Subjects included 100 patients with arthritis and 60 board-certified orthopedic surgeon physicians in South Korea. Through a systematic review of the literature, beneficial attributes of using Cox-2 inhibitors were defined as a decrease in the Western Ontario and McMaster Universities Arthritis Index for pain score and improvement in physical function. Likewise, risk attributes included upper gastrointestinal (GI) complications and cardiovascular (CV) adverse events. Discrete choice experiments were used to determine preferences for these four attributes among Korean patients and physicians. Relative importance and maximum acceptable risk for improving beneficial attributes were assessed by analyzing the results of the discrete choice experiment by using a conditional logit model. Results Patients ranked the relative importance of benefit–risk attributes as follows: pain reduction (35.2%); physical function improvement (30.0%); fewer CV adverse events (21.5%); fewer GI complications (13.4%). The physicians’ ranking for the same attributes was as follows: fewer CV (33.5%); pain reduction (32.4%); fewer GI complications (18.1%); physical function improvement (16.0%). Patients were more willing than physicians to accept risks when pain improved from 20% or 45% to 55% and physical function improved from 15% or 35% to 45%. Conclusion We confirmed that patients and physicians had different benefit–risk preferences regarding Cox-2 inhibitors. Patients with arthritis prioritized the benefits of Cox-2 inhibitors over the risks; moreover, in comparison with the physicians, arthritis patients were more willing to accept the trade-off between benefits and risks to achieve the best treatment level. To reduce the preference gap and achieve treatment goals, physicians must better

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

    PubMed

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

    2005-05-01

    The anti-tumor effect of cyclo-oxygenase (COX) inhibitors has been documented in several studies. COX2 inhibitors have attracted more attention because of the fewer side-effects and the more prominent anti-tumor effects. However, experience with these drugs in hematological malignancies is limited. In our study, a potent COX2 inhibitor, nabumetone (NBT), was investigated for its anti-proliferative and apoptotic effects in K-562 and Meg-01 chronic myeloid leukemia blastic cell lines as a single agent or in combination with adriamycin (ADR) and interferon alpha (IFN-a). In these cell lines, a dose-dependent inhibition of proliferation was observed with NBT. We observed no significant apoptotic effect of NBT. However, NBT potentiated the apoptotic effect of ADR in the K-562 cell line. Bcl-2 expression was reduced by NBT (11% vs. 2%). The combination of NBT with IFN did not have any significant effect on the K-562 cell line. We suggest that NBT inhibits proliferation and potentiates the apoptotic effect of ADR in chronic myeloid leukemia cell lines. PMID:16019514

  7. [Cyclooxygenase-2 (Cox-2) selective inhibitors: socioeconomic and pharmaco-epidemiologic aspects].

    PubMed

    Ruof, J; Hülsemann, J L

    2000-04-01

    Health authorities of several European countries recently introduced guidelines for socioeconomic evaluations. Additionally the activities of OMERACT (Outcome Measures in Rheumatoid Arthritis Clinical Trials) indicate an increasing awareness for the need of socioeconomic studies in rheumatology. The planned 2000 OMERACT meeting in Toulouse will address transfer of socioeconomic standards into rheumatology. In terms of cost effectiveness of selective Cox-2 inhibitors, a reference has to be made to the preceding discussion of cost effectiveness of Misoprostol. In addition, there are two models examining the cost effectiveness of Cox-2 inhibitors: a Canadian model comparing Nabumetone and Naproxen and an unpublished model assessing the cost effectiveness of Celecoxib (ACCES: Arthritis Cost Consequence Evaluation System). German data indicate that gastrointestinal bleedings account for 32.9% of all adverse drug events leading to a hospital admission. Further data assessing the morbidity due to adverse effects of nonsteroidal anti-inflammatory drugs are needed. Such data would allow the quantification of possible savings related to the usage of Cox-2 inhibitors in Germany. PMID:10868021

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

    SciTech Connect

    Jun, Hyun Jung; Kim, Young Mee; Park, Soo Yeon; Park, Ji Sun; Lee, Eun Jung; Choi, Shin Ae; Pyo, Hongryull

    2009-09-01

    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.

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

    PubMed

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

    2015-10-01

    Bioassay-guided fraction of the methanol extract of the roots of Pueraria tuberose DC yielded puerarin, an isoflavone C-glycoside (PT-1), isoorientin, a flavone C-glycoside (PT-2) and mangiferin, a xanthone C-glycoside (PT-3). The extracts and the isolated compounds were screened for potent anti-inflammatory components inhibiting the cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX), the target enzymes of inflammation, by employing spectroscopic/polorographic methods. Among these, isoorientin was found to be a potent inhibitor of COX-2with an IC50 value of 39 μM. Docking studies were carried out to understand the interactions of isorientin (PT-2) with COX-2.The structures of the isolates were determined by mass spectrometry and 2D-NMR techniques including HSQC, HMBC, NOESY and 1H-1H COSY experiments. Although isoorientin and mangiferin have been reported from several plant sources, this is the first report of their isolation from a Pueraria species. PMID:26669106

  10. Reduction in cancer risk by selective and nonselective cyclooxygenase-2 (COX-2) inhibitors

    PubMed Central

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

    2012-01-01

    We conducted a series of epidemiologic studies to evaluate the chemopreventive effects of aspirin, ibuprofen, and selective cyxlooxygenase-2 (COX-2) inhibitors (coxibs) against cancers of the breast, colon, prostate, and lung. Composite results across all four cancer sites revealed that regular intake of 325 mg aspirin, 200 mg ibuprofen, or standard dosages of coxibs (200 mg celecoxib or 25 mg rofecoxib) produced risk reductions of 49%, 59%, and 64%, respectively. Use of coxibs for at least 2 years was associated with risk reductions of 71%, 70%, 55%, and 60% for breast cancer, colon cancer, prostate cancer and lung cancer, respectively. Effects of ibuprofen were similar to selective coxibs, and slightly stronger than aspirin. These observed effects are consistent with the relative COX-2 selectivity of ibuprofen, coxibs, and aspirin. Acetaminophen, an analgesic without COX-2 activity, had no effect. Overexpression of COX-2 and increased prostaglandin biosynthesis correlates with carcinogenesis and metastasis at most anatomic sites. These results indicate that regular intake of nonselective or selective COX-2 inhibiting agents protects against the development of major forms of cancer.

  11. Clinical pharmacology of lumiracoxib: a selective cyclo-oxygenase-2 inhibitor.

    PubMed

    Rordorf, Christiane M; Choi, Les; Marshall, Paul; Mangold, James B

    2005-01-01

    Lumiracoxib (Prexige) is a selective cyclo-oxygenase (COX)-2 inhibitor developed for the treatment of osteoarthritis, rheumatoid arthritis and acute pain. Lumiracoxib possesses a carboxylic acid group that makes it weakly acidic (acid dissociation constant [pKa] 4.7), distinguishing it from other selective COX-2 inhibitors. Lumiracoxib has good oral bioavailability (74%). It is rapidly absorbed, reaching maximum plasma concentrations 2 hours after dosing, and is highly plasma protein bound. Lumiracoxib has a short elimination half-life from plasma (mean 4 hours) and demonstrates dose-proportional plasma pharmacokinetics with no accumulation during multiple dosing. In patients with rheumatoid arthritis, peak lumiracoxib synovial fluid concentrations occur 3-4 hours later than in plasma and exceed plasma concentrations from 5 hours after dosing to the end of the 24-hour dosing interval. These data suggest that lumiracoxib may be associated with reduced systemic exposure, while still reaching sites where COX-2 inhibition is required for pain relief. Lumiracoxib is metabolised extensively prior to excretion, with only a small amount excreted unchanged in urine or faeces. Lumiracoxib and its metabolites are excreted via renal and faecal routes in approximately equal amounts. The major metabolic pathways identified involve oxidation of the 5-methyl group of lumiracoxib and/or hydroxylation of its dihaloaromatic ring. Major metabolites of lumiracoxib in plasma are the 5-carboxy, 4'-hydroxy and 4'-hydroxy-5-carboxy derivatives, of which only the 4'-hydroxy derivative is active and COX-2 selective. In vitro, the major oxidative pathways are catalysed primarily by cytochrome P450 (CYP) 2C9 with very minor contribution from CYP1A2 and CYP2C19. However, in patients genotyped as poor CYP2C9 metabolisers, exposure to lumiracoxib (area under the plasma concentration-time curve) is not significantly increased compared with control subjects, indicating no requirement for adjustment

  12. Cell cycle regulation and apoptotic cell death in experimental colon carcinogenesis: intervening with cyclooxygenase-2 inhibitors.

    PubMed

    Saini, Manpreet Kaur; Sanyal, Sankar Nath

    2015-01-01

    Relative imbalance in the pathways regulating cell cycle, cell proliferation, or cell death marks a prerequisite for neoplasm. C-phycocyanin, a biliprotein from Spirulina platensis and a selective COX-2 inhibitor along with piroxicam, a traditional nonsteroidal antiinflammatory drug was used to investigate the role of cell cycle regulatory proteins and proinflammatory transcription factor NFκB in 1,2-dimethylhydrazine dihydrochloride (DMH)-induced rat colon carcinogenesis. Cell cycle regulators [cyclin D1, cyclin E, cyclin dependent kinase 2 (CDK2), CDK4, and p53], NFκB (p65) pathway, and proliferating cell nuclear antigen (PCNA) were evaluated by gene and protein expression, whereas apoptosis was studied by terminal deoxynucleotidyl transferase dUTP nick end labeling and apoptotic bleb assay. Molecular docking of ligand protein interaction was done to validate the in vivo results. Cyclin D1, cyclin E, CDK2, and CDK4 were overexpressed in DMH, whereas piroxicam and c-phycocyanin promoted the cell cycle arrest by downregulating them. Both drugs mediated apoptosis through p53 activation. Piroxicam and c-phycocyanin also stimulated antiproliferation by restraining PCNA expression and reduced cell survival via inhibiting NFκB (p65) pathway. Molecular docking revealed that phycocyanobilin (a chromophore of c-phycocyanin) interact with DNA binding site of NFκB. Inhibition of cyclin/CDK complex by piroxicam and c-phycocyanin affects the expression of p53 in colon cancer followed by downregulation of NFκB and PCNA levels, thus substantiating the antineoplastic role of these agents. PMID:25825916

  13. Cyclooxygenase-2 inhibitor, nimesulide, improves radiation treatment against non-small cell lung cancer both in vitro and in vivo.

    PubMed

    Grimes, Kristopher R; Warren, Graham W; Fang, Fang; Xu, Yong; St Clair, William H

    2006-10-01

    Lung cancer is the leading cause of cancer-related deaths in the United States. Despite improvements in radiation, surgery and chemotherapy the 5 year survival statistics of non-small cell lung cancer (NSCLC) have improved little over the past two decades. It has been proposed that NF-kappaB is a participant in the cytoprotection against several redox-mediated therapeutic agents including ionizing radiation. Cyclooxygenase-2 (COX-2) inhibition has become an attractive target for enhancing the efficacy of radiation and chemotherapy. Numerous mechanistic pathways have been proposed as the means through which COX-2 inhibition enhances the efficacy of radiation. We hypothesize that the COX-2 inhibitor, nimesulide, will improve the efficacy of radiation therapy (RT), at least in part, via the suppression of NF-kappaB mediated cytoprotective pathways. In this study we used the COX-2 inhibitor nimesulide to improve the efficacy of RT when measured by tumor regrowth assays in vivo and clonegenic survival in vitro. For the in vivo assay, A549 tumor cells representing NSCLC were subcutaneously injected into the right flanks of female athymic nude mice (n=10/group). Mice were given nimesulide via drinking water at a concentration of 5 microg/g body weight (b.w.) and the water was replenished daily. Tumors were treated with 30 Gy fractionated radiation and measured bi-weekly. For our in vitro study, clonogenic survival assays were evaluated to determine the effect of nimesulide, radiation, and the combination. The NF-kappaB mediated mechanism of nimesulide was measured by Western blot analysis of NF-kappaB target genes, MnSOD and survivin. In vivo, mice that received combined treatments of 5 microg/g b.w. nimesulide and 30 Gy radiation (3 Gy/fraction, 10 daily fractions) had significant reduction in tumor size in comparison to the 30 Gy radiation control group (p<0.05). In vitro, nimesulide alone produced a significant decrease in clonogenic survival at doses from 0-300 micro

  14. Synthesis of new thiazolo-celecoxib analogues as dual cyclooxygenase-2/15-lipoxygenase inhibitors: Determination of regio-specific different pyrazole cyclization by 2D NMR.

    PubMed

    Abdelall, Eman K A; Kamel, Gehan M

    2016-08-01

    Two new series of 1,5-diaryl pyrazoles (5a, 5b, 7a, 7b and 10) and 1,5-diaryl pyrazoline (12a and 12b) were prepared as both Cyclooxygenase-2 and 15-lipoxygenase inhibitors. Carrageenan-induced rat paw edema, ulcer index and anti-COX-1/COX-2 and 15-LOX inhibition assays were also included. Cyclization of different pyrazoles was discussed using 2D NMR such as HSQC, HMBC and NOSEY determinations. Compound 5a is more effective with ED50 = 0.98 and 3.98 μM against COX-2 and 15-lipoxygenase respectively, than the references celecoxib (1.54 μM) and meclofenamate sodium (5.64 μM). PMID:27131067

  15. Meloxicam, an inhibitor of cyclooxygenase-2, increases the level of serum G-CSF and might be usable as an auxiliary means in G-CSF therapy.

    PubMed

    Hofer, M; Pospísil, M; Znojil, V; Holá, J; Vacek, A; Streitová, D

    2008-01-01

    Hematopoiesis-modulating action of meloxicam, a cyclooxyge-nase-2 inhibitor, has been evaluated in mice. Increased serum level of granulocyte colony-stimulating factor (G-CSF) after meloxicam administration has been found in sublethally gamma-irradiated animals. In further experiments hematopoiesis-stimulating effects of meloxicam and G-CSF given alone or in combination have been investigated. Granulocyte/macrophage progenitor cells counts were used to monitor these effects. Meloxicam and exogenous G-CSF did not act synergistically when given in combination, but could be mutually substituted during their repeated administration. The results suggest a promising possibility of using meloxicam as an auxiliary drug reducing the high costs of G-CSF therapy of myelosuppression. PMID:17552878

  16. Analgesic Efficacy of Firocoxib, a Selective Inhibitor of Cyclooxygenase 2, in a Mouse Model of Incisional Pain

    PubMed Central

    Reddyjarugu, Balagangadharreddy; Pavek, Todd; Southard, Teresa; Barry, Jason; Singh, Bhupinder

    2015-01-01

    Pain management in laboratory animals is generally accomplished by using opioids and NSAIDs. However, opioid use is hindered by controlled substance requirements and a relatively short duration of action. In this study, we compared the analgesic efficacy of firocoxib (a cyclooxygenase-2-selective NSAID) with that of buprenorphine in the mouse model of plantar incisional pain by objective measurement of mechanical allodynia and thermal hyperalgesia using von Frey and Hargreaves equipment, respectively. Our experimental design included 5 treatment groups: firocoxib at 10 mg/kg IP every 24 h (F10 group); firocoxib at 20 mg/kg IP every 24 h (F20); buprenorphine at 0.2 mg/kg SC every 8 h; intraperitoneal normal saline every 24 h; and sham group (anesthesia, no incision) treated with firocoxib at 20 mg/kg IP every 24 h (sham+F20). All mice underwent nociceptive assays at 24 h before and 4, 24, 48, and 72 h after surgery. Buprenorphine alleviated allodynia at all time points after incision. The F10 treatment alleviated allodynia at 4, 24, and 48 h, whereas F20 alleviated allodynia at 24, 48, and 72 h. None of the treatments alleviated thermal hyperalgesia at 4h. Except for F10 and buprenorphine at 24 h, all treatments alleviated thermal hyperalgesia at 24, 48, and 72 h. No significant differences were noted between the 2 doses of firocoxib and buprenorphine regarding mechanical allodynia and thermal hyperalgesia at all time points. In conclusion, the analgesic efficacy of firocoxib is comparable to that of buprenorphine in this mouse pain model. PMID:26224441

  17. Design, Synthesis, and Biological Evaluation of New 2-Phenyl-4H-chromen-4-one Derivatives as Selective Cyclooxygenase-2 Inhibitors.

    PubMed

    Zarghi, Afshin; Kakhki, Samaneh

    2015-01-01

    In order to develop new selective COX-2 inhibitors, a new series of 2-phenyl-4H-chromen-4-one derivatives possessing a methylsulfonyl pharmacophore group at the para position of the C-4 phenyl ring were designed, synthesized, and evaluated for cyclooxygenase-2 inhibitory activity. In vitro COX-1/COX-2 isozyme inhibition structure-activity studies identified 3-(benzyloxy)-2-[4-(methylsulfonyl)phenyl]-4H-chromen-4-one (5d) as a potent COX-2 inhibitor (IC50 = 0.07 μM) with a high COX-2 selectivity index (SI = 287.1) comparable to the reference drug celecoxib (COX-2 IC50 = 0.06 μM; COX-2 SI = 405). A molecular modeling study where 3-(benzyloxy)-2-[4-(methylsulfonyl)phenyl]-4H-chromen-4-one (5d) was docked into the active site of COX-2 showed that the p-MeSO2 substituent on the C-4 phenyl ring was well-oriented in the vicinity of the COX-2 secondary pocket (Arg(513), Val(523), and His(90)) and the carbonyl group of the chromene ring could interact with Ser(530). The structure-activity data acquired indicated that the nature and size of the substituent on the C-3 chromene scaffold are important for COX-2 inhibitory activity. Our results also indicated that the chromene moiety constitutes a suitable template to design new COX-2 inhibitors. PMID:26839798

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

    PubMed Central

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

    2014-01-01

    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

  19. Cyclooxygenase-2 or tumor necrosis factor-α inhibitors attenuate the mechanotransductive effects of pulsed focused ultrasound to suppress mesenchymal stromal cell homing to healthy and dystrophic muscle

    PubMed Central

    Tebebi, Pamela A.; Burks, Scott R.; Kim, Saejeong J.; Williams, Rashida A.; Nguyen, Ben A.; Venkatesh, Priyanka; Frenkel, Victor; Frank, Joseph A.

    2014-01-01

    Maximal homing of infused stem cells to diseased tissue is critical for regenerative medicine. Pulsed focused ultrasound (pFUS) is a clinically relevant platform to direct stem cell migration. Through mechanotransduction, pFUS establishes local gradients of cytokines, chemokines, trophic factors (CCTF) and cell adhesion molecules (CAM) in treated skeletal muscle that subsequently infused mesenchymal stromal cells (MSC) can capitalize to migrate into the parenchyma. Characterizing molecular responses to mechanical pFUS effects revealed tumor necrosis factor-alpha (TNFα) drives cyclooxygenase-2 (COX2) signaling to locally increase CCTF/CAM that are necessary for MSC homing. pFUS failed to increase chemoattractants and induce MSC homing to treated muscle in mice pretreated with ibuprofen (non-specific COX inhibitor) or etanercept (TNFα inhibitor). pFUS-induced MSC homing was also suppressed in COX2-knockout mice, demonstrating ibuprofen blocked the mechanically-induced CCTF/CAM by acting on COX2. Anti-inflammatory drugs, including ibuprofen, are administered to muscular dystrophy (MD) patients and ibuprofen also suppressed pFUS-induced homing to muscle in a mouse model of MD. Drug interactions with cell therapies remain unexplored and are not controlled for during clinical cell therapy trials. This study highlights potentially negative drug-host interactions that suppress stem cell homing and could undermine cell-based approaches for regenerative medicine. PMID:25534849

  20. Selective cyclooxygenase-2 inhibitors show a differential ability to inhibit proliferation and induce apoptosis of colon adenocarcinoma cells.

    PubMed

    Yamazaki, Ryuta; Kusunoki, Natsuko; Matsuzaki, Takeshi; Hashimoto, Shusuke; Kawai, Shinichi

    2002-11-01

    Although the influence of selective cyclooxygenase (COX)-2 inhibitors on the proliferation of colon adenocarcinoma cells have been the subject of much investigation, relatively little research has compared the effects of different COX-2 inhibitors. Celecoxib strongly suppressed the proliferation of COX-2 expressing HT-29 cells at 10-40 microM. NS-398 and nimesulide also inhibited cell proliferation, whereas rofecoxib, meloxicam, and etodolac did not. Only celecoxib induced apoptosis of HT-29 cells, as detected on the basis of DNA fragmentation, TUNEL positivity, and caspase-3/7 activation. DNA fragmentation was also increasd in COX-2 non-expressing cell lines (SW-480 and HCT-116) by exposure to celecoxib for 6-24 h. All six COX-2 inhibitors suppressed the production of prostaglandin E(2) by HT-29 cells, suggesting that the pro-apoptotic effect of celecoxib was unrelated to inhibition of COX-2. Inactivation of Akt might explain the differential pro-apoptotic effect of these selective COX-2 inhibitors on colon adenocarcinoma cells. PMID:12417326

  1. Magnetic ligand fishing combination with high-performance liquid chromatography-diode array detector-mass spectrometry to screen and characterize cyclooxygenase-2 inhibitors from green tea.

    PubMed

    Deng, Xu; Shi, Shuyun; Li, Simin; Yang, Tianlun

    2014-10-22

    Cyclooxygenase-2 (COX-2) inhibitors may be used to efficiently treat inflammation or cancer diseases. In the present study, we established a new screening assay based on magnetic Fe3O4@SiO2-COX-2 ligand fishing combination with high-performance liquid chromatography-diode array detector-mass spectrometry (HPLC-DAD-MS(n)) to screen and identify COX-2 inhibitors from green tea. Optimized conditions (pH at 7.4, temperature at 30°C, and incubation time for 30min) for fishing out COX-2 inhibitors were achieved by testing positive control, celecoxib, with active and inactive COX-2. Notably, immobilized COX-2 showed high stability (remained 94.7% after ten consecutive cycles), reproducibility (RSD<10% for batch-to-batch evaluation). Finally, eight catechins with COX-2 binding activity were screened in green tea, and their structures were characterized by ultraviolet (UV), accurate molecular weight, diagnostic fragment ions and nuclear magnetic resonance (NMR). Particularly, the COX-2 inhibitory activities of two rare catechins, [(-)-epigallocatechin-3-(3″-O-methyl)-gallate (3″-O-methyl-EGCG, IC50=0.17±0.03μM 0.16±0.01), (-)-epicatechin-3-(3″-O-methyl)-gallate (3″-O-methyl-ECG, IC50=0.16±0.02μM)], were reported for the first time. The results indicated that the proposed method was a simple, robust and reproducible approach for the discovery of COX-2 inhibitors from complex matrix. PMID:25464095

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

    PubMed Central

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

    2011-01-01

    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 μM; selectivity index > 1298). It was more selective than the reference drug celecoxib (COX-2 IC50 = 0.060 μM; 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. PMID:21886896

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

    PubMed Central

    Lohsiriwat, Varut

    2016-01-01

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

  4. Celecoxib, a cyclooxygenase-2 inhibitor, potentiates the chemotherapic effect of vinorelbine in the medullary thyroid cancer TT cell line.

    PubMed

    Vivaldi, A; Ciampi, R; Tacito, A; Molinaro, E; Agate, L; Bottici, V; Pinchera, A; Collecchi, P; Elisei, R

    2012-05-15

    We analyzed the in vitro effects of celecoxib, a COX-2 inhibitor, and determined if celecoxib can sensitize a human MTC-derived cell line (TT) to chemotherapeutics. We found that celecoxib induced apoptosis in TT cells and decreased drug efflux by reducing the expression of MDR-1 mRNA, which codes for the drug efflux pump P-gp. We also observed that TT cells were 10-fold more resistant to doxorubicin than to vinorelbine, mimicking what can be observed in clinical practice. In addition, we found that the combination of celecoxib and vinorelbine, but not doxorubicin, induced a significant reduction in cell viability and a significant increase in apoptosis. In conclusion, we showed that celecoxib was able to enhance the chemotherapeutic effect of vinorelbine. A clinical trial exploring the in vivo activities of celecoxib in MTC patients who cannot benefit from available treatments would be desirable, taking into account the possible risks of cardiovascular effects of this drug. PMID:22305971

  5. The effects of nabumetone, a cyclooxygenase-2 inhibitor, on cisplatin-induced 5-hydroxytryptamine release from the isolated rat ileum.

    PubMed

    Kudo, C; Minami, M; Hirafuji, M; Endo, T; Hamaue, N; Akita, K; Murakami, T; Kawaguchi, H

    2001-01-01

    In order to elucidate 5-HT release influenced by PGE2 in the background of the anticancer drug-induced emesis, the effect of nabumetone, a COX-2 inhibitor, on the release of 5-HT from the isolated rat ileum was investigated. PGE2 produced a concentration-dependent increase (10(-9) to 10 M) and decrease (10(-8) to 10(-6) M) in 5-HT release. Arachidonic acid also demonstrated a similar bell-shaped 5-HT release. The arachidonic acid-induced 5-HT release at 3 x 10(-6) M (313.04 +/- 25.90%) was significantly inhibited by the concomitant perfusion with BRL10720 (10(-6) M) (161.98 +/- 19.4%, p<0.01), an active metabolite of nabumetone, or indomethacin (3 x 10(-7) M)(190.01 +/- 16.19%, p<0.05). BRL10720 (10(-6) M)(428.57 +/- 51.72%, p<0.05) significantly inhibited the increase in 5-HT release induced by cisplatin (10(-6) M)(748.56 +/- 136.31%), suggesting that PGE2would be involved in cisplatin-induced 5-HT release. The increase in 5-HT release from the isolated ileum 72 hrs after cisplatin administration, in a delayed-emesis animal model, was significantly inhibited by the in vivo 3-day administration of nabumetone or BRL10720, but was not affected by the 3-day administration of dexamethasone. After 72 hours, however, the in vivo 3-days administration of nabumetone, BRL10720 or dexamethasone had no effect on the increase in ileal 5-HT levels induced by cisplatin. The use of COX-2 inhibitors to ameliorate delayed emesis induced by cisplatin-based anticancer chemotherapy has been proposed. On the other hand, there is a possibility that dexamethasone works through a mechanism other than 5-HT release in delayed emesis. PMID:12090350

  6. Novel di-tertiary-butyl phenylhydrazones as dual cyclooxygenase-2/5-lipoxygenase inhibitors: synthesis, COX/LOX inhibition, molecular modeling, and insights into their cytotoxicities.

    PubMed

    Ghatak, Shibnath; Vyas, Alok; Misra, Suniti; O'Brien, Paul; Zambre, Ajit; Fresco, Victor M; Markwald, Roger R; Swamy, K Venkateshwara; Afrasiabi, Zahra; Choudhury, Amitava; Khetmalas, Madhukar; Padhye, Subhash

    2014-01-01

    Although dual inhibition of Cyclooxygenase-2 (COX-2) and 5-Lipoxygenase (5-LOX) enzymes is highly effective than targeting COX or LOX alone, there are only a few reports of examining such compounds in case of colorectal cancers (CRC). In the present work we report that the novel di-tert-butyl phenol-based dual inhibitors DTPSAL, DTPBHZ, DTPINH, and DTPNHZ exhibit significant cytotoxicity against human CRC cell lines. Molecular docking studies revealed a good fit of these compounds in the COX-2 and 5-LOX protein cavities. The inhibitors show significant inhibition of COX-2 and 5-LOX activities and are effective against a panel of human colon cancer cell lines including HCA-7, HT-29, SW480 and intestinal Apc10.1 cells as well as the hyaluronan synthase-2 (Has2) enzyme over-expressing colon cancer cells, through inhibition of the Hyaluronan/CD44v6 cell survival pathway. Western blot analysis and qRT-PCR analyses indicated that the di-tert-butyl phenol-based dual inhibitors reduce the expression of COX-2, 5-LOX, and CD44v6 in human colon cancer HCA-7 cells, while the combination of CD44v6shRNA and DTPSAL has an additional inhibitory effect on CD44v6 mRNA expression. The synergistic inhibitory effect of Celecoxib and Licofelone on CD44v6 mRNA expression suggests that the present dual inhibitors down-regulate cyclooxygenase and lipoxygenase enzymes through CD44v6. The compounds also exhibited enhanced antiproliferative potency compared to standard dual COX/LOX inhibitor, viz. Licofelone. Importantly, the HA/CD44v6 antagonist CD44v6shRNA in combination with synthetic compounds had a sensitizing effect on the cancer cells which enhanced their antiproliferative potency, a finding which is crucial for the anti-proliferative potency of the novel synthetic di-tert-butyl phenol based dual COX-LOX inhibitors in colon cancer cells. PMID:24295787

  7. Mechanisms underlying the growth inhibitory effects of the cyclo-oxygenase-2 inhibitor celecoxib in human breast cancer cells

    PubMed Central

    Basu, Gargi D; Pathangey, Latha B; Tinder, Teresa L; Gendler, Sandra J; Mukherjee, Pinku

    2005-01-01

    Introduction Inhibitors of cyclo-oxygenase (COX)-2 are being extensively studied as anticancer agents. In the present study we evaluated the mechanisms by which a highly selective COX-2 inhibitor, celecoxib, affects tumor growth of two differentially invasive human breast cancer cell lines. Methods MDA-MB-231 (highly invasive) and MDA-MB-468 (moderately invasive) cell lines were treated with varying concentrations of celecoxib in vitro, and the effects of this agent on cell growth and angiogenesis were monitored by evaluating cell proliferation, apoptosis, cell cycle arrest, and vasculogenic mimicry. The in vitro results of MDA-MB-231 cell line were further confirmed in vivo in a mouse xenograft model. Results The highly invasive MDA-MB-231 cells express higher levels of COX-2 than do the less invasive MDA-MB-468 cells. Celecoxib treatment inhibited COX-2 activity, indicated by prostaglandin E2 secretion, and caused significant growth arrest in both breast cancer cell lines. In the highly invasive MDA-MB-231 cells, the mechanism of celecoxib-induced growth arrest was by induction of apoptosis, associated with reduced activation of protein kinase B/Akt, and subsequent activation of caspases 3 and 7. In the less invasive MDA-MB-468 cells, growth arrest was a consequence of cell cycle arrest at the G0/G1 checkpoint. Celecoxib-induced growth inhibition was reversed by addition of exogenous prostaglandin E2 in MDA-MB-468 cells but not in MDA-MB-231 cells. Furthermore, MDA-MB-468 cells formed significantly fewer extracellular matrix associated microvascular channels in vitro than did the high COX-2 expressing MDA-MB-231 cells. Celecoxib treatment not only inhibited cell growth and vascular channel formation but also reduced vascular endothelial growth factor levels. The in vitro findings corroborated in vivo data from a mouse xenograft model in which daily administration of celecoxib significantly reduced tumor growth of MDA-MB-231 cells, which was associated with

  8. Analgesic efficacy of the cyclooxygenase-2-specific inhibitor rofecoxib in post-dental surgery pain: a randomized, controlled trial.

    PubMed

    Morrison, B W; Christensen, S; Yuan, W; Brown, J; Amlani, S; Seidenberg, B

    1999-06-01

    Previous data have suggested that rofecoxib, a cyclooxygenase (COX)-2-specific inhibitor, had analgesic effects similar to those of the nonsteroidal anti-inflammatory drugs when tested in the post-dental surgery pain model. The objective of this parallel-group, double-masked, randomized, placebo- and active comparator-controlled clinical trial was to assess more fully the analgesic efficacy of rofecoxib in the treatment of postoperative dental pain. After dental surgery, 151 patients (50.3% women; mean age, 18.3 years; 93.4% white) experiencing moderate-to-severe pain were to receive a single dose of placebo, rofecoxib 50 mg, or ibuprofen 400 mg. Analgesic efficacy was assessed for up to 24 hours postdose using self-administered questionnaires. Tolerability was assessed using spontaneous reports of adverse experiences, physical findings, and laboratory measurements. The results of this study demonstrated that rofecoxib 50 mg was more effective than placebo on all measures of analgesic efficacy. Rofecoxib 50 mg exhibited overall analgesic effects, onset of analgesia, and peak analgesic effects that were not significantly different from those of ibuprofen 400 mg, with a significantly longer duration of action (P < 0.05). We concluded that rofecoxib was efficacious in the treatment of postoperative dental pain and that COX-2-derived prostanoids play a role in treatment of the pain associated with dental surgery. PMID:10440619

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

    SciTech Connect

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

    2005-08-26

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

  10. Kainic acid-induced neurodegeneration and activation of inflammatory processes in organotypic hippocampal slice cultures: treatment with cyclooxygenase-2 inhibitor does not prevent neuronal death.

    PubMed

    Järvelä, Juha T; Ruohonen, Saku; Kukko-Lukjanov, Tiina-Kaisa; Plysjuk, Anna; Lopez-Picon, Francisco R; Holopainen, Irma E

    2011-06-01

    In the postnatal rodent hippocampus status epilepticus (SE) leads to age- and region-specific excitotoxic neuronal damage, the precise mechanisms of which are still incompletely known. Recent studies suggest that the activation of inflammatory responses together with glial cell reactivity highly contribute to excitotoxic neuronal damage. However, pharmacological tools to attenuate their activation in the postnatal brain are still poorly elucidated. In this study, we investigated the role of inflammatory mediators in kainic acid (KA)-induced neuronal damage in organotypic hippocampal slice cultures (OHCs). A specific cyclooxygenase-2 (COX-2) inhibitor N-[2-(cyclohexyloxy)-4-nitrophenyl]-methanesulfonamide (NS-398) was used to study whether or not it could ameliorate neuronal death. Our results show that KA treatment (24 h) resulted in a dose-dependent degeneration of CA3a/b pyramidal neurons. Furthermore, COX-2 immunoreactivity was pronouncedly enhanced particularly in CA3c pyramidal neurons, microglial and astrocyte morphology changed from a resting to active appearance, the expression of the microglial specific protein, Iba1, increased, and prostaglandin E₂ (PGE₂) production increased. These indicated the activation of inflammatory processes. However, the expression of neither proinflammatory cytokines, i.e. tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), nor the anti-inflammatory cytokine IL-10 mRNA was significantly altered by KA treatment as studied by real-time PCR. Despite activation of an array of inflammatory processes, neuronal damage could not be rescued either with the combined pre- and co-treatment with a specific COX-2 inhibitor, NS-398. Our results suggest that KA induces activation of a repertoire of inflammatory processes in immature OHCs, and that the timing of anti-inflammatory treatment to achieve neuroprotection is a challenge due to developmental properties and the complexity of inflammatory processes activated by

  11. Improving survival rates in two models of spontaneous postoperative metastasis in mice by combined administration of a beta-adrenergic antagonist and a cyclooxygenase-2 inhibitor.

    PubMed

    Glasner, Ariella; Avraham, Roi; Rosenne, Ella; Benish, Marganit; Zmora, Oded; Shemer, Shaily; Meiboom, Hadas; Ben-Eliyahu, Shamgar

    2010-03-01

    Clinical practice does not consider perioperative paracrine and neuroendocrine stress responses as risk factors for cancer recurrence, although recent animal studies provided supportive evidence. Suggested mechanisms include the effects of stress-hormones on tumor cells and on host physiology. In this study, in mice undergoing primary tumor excision, we tested the survival-enhancing potential of perioperative blockade of catecholamines and prostaglandins, and studied potential mediating mechanisms. C57BL/6J mice were inoculated intrafootpad with syngeneic B16F10.9-melanoma or Lewis lung carcinoma, and the paw was amputated when a developing tumor exceeded 100 microl. The clinically used beta-adrenergic antagonist propranolol, and/or the cyclooxygenase-2 inhibitor etodolac, were administered once before amputation, and recurrence-free survival was monitored. In different studies, NK cytotoxicity, leukocytes' molecular functional markers, and vascular endothelial growth factor secretion by tumor cells were studied in the context of surgery and drug treatments. The findings indicated that the combination of propranolol and etodolac, but neither drug alone, significantly and markedly improved survival rates in both tumor models, and was as effective as established immunostimulatory agents (IL-12 and polyinosinic-polycytiylic acid). Surgery markedly reduced NK cytotoxicity and NK cell expression of Fas ligand and CD11a, reduced all circulating lymphocyte-subtype concentrations, and increased corticosterone levels. Propranolol and etodolac administration counteracted these perturbations. B16 and 3LL secreted vascular endothelial growth factor in vitro, but secretion was not affected by catecholamine agonists, prostaglandins, corticosterone, propranolol, or etodolac. Overall, propranolol and etodolac administration, which could be applied perioperatively in most cancer patients with minimal risk and low cost, has counteracted several immunologic and endocrinologic

  12. 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

    Raju, Uma . E-mail: uraju@mdanderson.org; Ariga, Hisanori; Dittmann, Klaus; Nakata, Eiko; Ang, Kian K.; Milas, Luka

    2005-10-01

    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

  13. The cyclin-dependent kinase 2 inhibitor down-regulates interleukin-1beta-mediated induction of cyclooxygenase-2 expression in human lung carcinoma cells.

    PubMed

    Mukhopadhyay, Partha; Ali, M Aktar; Nandi, Animesh; Carreon, Peter; Choy, Hak; Saha, Debabrata

    2006-02-01

    Overexpression of cyclooxygenase-2 (COX-2) is frequently observed in several human cancers, including lung, colon, and head and neck. Malignancies are also associated with the dysregulation of cell cycle events and concomitant elevated activity of cyclin-dependent kinases (CDK). CDK2 is a key cell cycle regulatory protein that controls the transition of cells from G(1) to S phase. In this study, we furnish several lines of evidence that show a functional role for the CDK2 in interleukin-1beta (IL-1beta)-induced COX-2 expression in H358 human non-small cell lung carcinoma cell line by blocking CDK2 activity. First, we show that BMS-387032, a potent CDK2 inhibitor, blocks IL-1beta-induced expression as well as steady-state mRNA levels of COX-2. Second, we show that small interfering RNA that abrogates CDK2 expression also blocks IL-1beta-induced COX-2 expression. Third, results from in vitro kinase assays clearly show that IL-1beta induces CDK2 activity in H358 cells and this activity is significantly inhibited by BMS-387032. Moreover, CDK2 inhibition blocks IL-1beta-induced binding to the NF-IL6 element of the COX-2 promoter and inhibits transcription of the COX-2 gene. We also observed that BMS-387032 does not inhibit endogenous expression of COX-2 or prostaglandin synthesis in lung carcinoma cells. Finally, we provide evidence showing that IL-1beta-induced signaling events, such as p38 mitogen-activated protein kinase, phosphorylated stress-activated protein kinase/c-Jun NH(2)-terminal kinase, phosphorylated AKT, and phosphorylated extracellular signal-regulated kinase 1/2, are not inhibited by CDK2 inhibitor. Taken together, the data suggest that CDK2 activity may play an important event in the IL-1beta-induced COX-2 expression and prostaglandin E(2) synthesis and might represent a novel target for BMS-387032. PMID:16452236

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

    PubMed

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

    2013-02-01

    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

  15. Selective cyclo-oxygenase-2 inhibitors and their influence on the protective effect of a mild irritant in the rat stomach

    PubMed Central

    Gretzer, Britta; Ehrlich, Karlheinz; Maricic, Nenad; Lambrecht, Nils; Respondek, Michael; Peskar, Brigitta M

    1998-01-01

    The effects of the non-selective cyclo-oxygenase (COX) inhibitor indomethacin and the selective COX-2 inhibitors, N-[2-(cyclohexyloxy)-4-nitrophenyl] methanesulphonamide (NS-398), 5-methanesulphonamido-6-(2,4-difluorothio-phenyl)-1-indanone (L-745,337) and 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl) phenyl-2(5H)-furanone (DFU), on the protection induced by the mild irritant 20% ethanol were investigated in the rat stomach.Instillation of 20% ethanol (1 ml, p.o.) effectively protected against gastric mucosal injury induced by subsequent instillation of 70% or 96% ethanol (1 ml, p.o.).Oral administration of indomethacin (1.25–20 mg kg−1) dose-dependently counteracted the protective effect of 20% ethanol (ID50: 3.5 mg kg−1).Likewise, NS-398 (0.1–1 mg kg−1), L-745,337 (0.2–2 mg kg−1) and DFU (0.02–0.2 mg kg−1) inhibited the protective effect of 20% ethanol in a dose-dependent manner with ID50 values of 0.3 mg kg−1, 0.4 mg kg−1 and 0.06 mg kg−1, respectively.Inhibition of mild irritant-induced protection was also found when NS-398 (1 mg kg−1) was administered s.c. or when 96% ethanol was used to damage the mucosa.Pretreatment with 16,16-dimethyl-prostaglandin (PG)E2 at 4 ng kg−1, a dose that did not protect against ethanol (70%)-induced mucosal damage when given alone, completely reversed the effect of the selective COX-2 inhibitors on the mild irritant-induced protection.Pretreatment with dexamethasone (3 mg kg−1, 24 and 2 h before instillation of 20% ethanol) did not affect the protective activity of the mild irritant, indicating that enzyme induction is not involved.Indomethacin (20 mg kg−1, p.o.) did not prevent the protection conferred by sodium salicylate (100 mg kg−1), dimercaprol (30 μg kg−1), iodoacetamide (50 mg kg−1) and lithium (20 mg kg−1). Likewise, the protective effect of these agents was not counteracted by NS-398 (1 mg kg−1, p.o.).Whereas indomethacin (20

  16. QSAR of 2-(4-methylsulphonylphenyl)pyrimidine derivatives as cyclooxygenase-2 inhibitors: simple structural fragments as potential modulators of activity.

    PubMed

    Sharma, B K; Singh, P; Pilania, P; Shekhawat, M; Prabhakar, Y S

    2012-04-01

    The cyclooxygenase-2 (COX-2) inhibitory activity of 2-(4-methylsulphonylphenyl)pyrimidine derivatives has been quantitatively analyzed in terms of Dragon descriptors. The derived QSAR models have provided rationales to explain the activity of titled derivatives. The descriptors (Me, Mp, GATS1p and GATS5p) identified in CP-MLR analysis have highlighted the role of atomic properties, such as Sanderson electronegativity and polarizability, to explain the inhibitory activity. Additionally, prevalence of aromatic ether functionality (descriptor nRORPh) and certain structural fragments (number of Me groups, C-001; number of H attached to heteroatom, H-050 and number of H attached to α-C, H-051) in a molecular structure are helpful to rationalize the COX-2 inhibitory activity of pyrimidine derivatives. The partial least square (PLS) analysis has also confirmed the dominance of information content of CP-MLR-identified descriptors for modelling the activity. PMID:21679051

  17. New Inducible Nitric Oxide Synthase and Cyclooxygenase-2 Inhibitors, Nalidixic Acid Linked to Isatin Schiff Bases via Certain l-Amino Acid Bridges.

    PubMed

    Naglah, Ahmed M; Ahmed, Atallah F; Wen, Zhi-Hong; Al-Omar, Mohamed A; Amr, Abd El-Galil E; Kalmouch, Atef

    2016-01-01

    A series of new Schiff bases were synthesized by condensation of isatins with the nalidixic acid-l-amino acid hydrazides. Prior to hydrazide formation, a peptide linkage has been prepared via coupling of nalidixic acid with appropriate l-amino acid methyl esters to yield 3a-c. The chemical structures of the new Schiff bases (5b and 5d-h) were confirmed by means of IR, NMR, mass spectroscopic, and elemental analyses. The anti-inflammatory activity of these Schiff bases was evaluated via measurement of the expressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells model. The Schiff bases exhibited significant dual inhibitory effect against the induction of the pro-inflammatory iNOS and COX-2 proteins with variable potencies. However, they strongly down-regulated the iNOS expression to the level of 16.5% ± 7.4%-42.2% ± 19.6% compared to the effect on COX-2 expression (<56.4% ± 3.1% inhibition) at the same concentration (10 μM). The higher iNOS inhibition activity of the tested Schiff bases, relative to that of COX-2, seems to be a reflection of the combined suppressive effects exerted by their nalidixic acid, isatins (4a-c), and l-amino acid moieties against iNOS expression. These synthesized nalidixic acid-l-amino acid-isatin conjugates can be regarded as a novel class of anti-inflammatory antibacterial agents. PMID:27092477

  18. Evidence That Links Loss of Cyclooxygenase-2 With Increased Asymmetric Dimethylarginine

    PubMed Central

    Ahmetaj-Shala, Blerina; Kirkby, Nicholas S.; Knowles, Rebecca; Al’Yamani, Malak; Mazi, Sarah; Wang, Zhen; Tucker, Arthur T.; Mackenzie, Louise; Armstrong, Paul C. J.; Nüsing, Rolf M.; Tomlinson, James A. P.; Warner, Timothy D.; Leiper, James

    2015-01-01

    Background— Cardiovascular side effects associated with cyclooxygenase-2 inhibitor drugs dominate clinical concern. Cyclooxygenase-2 is expressed in the renal medulla where inhibition causes fluid retention and increased blood pressure. However, the mechanisms linking cyclooxygenase-2 inhibition and cardiovascular events are unknown and no biomarkers have been identified. Methods and Results— Transcriptome analysis of wild-type and cyclooxygenase-2−/− mouse tissues revealed 1 gene altered in the heart and aorta, but >1000 genes altered in the renal medulla, including those regulating the endogenous nitric oxide synthase inhibitors asymmetrical dimethylarginine (ADMA) and monomethyl-l-arginine. Cyclo-oxygenase-2−/− mice had increased plasma levels of ADMA and monomethyl-l-arginine and reduced endothelial nitric oxide responses. These genes and methylarginines were not similarly altered in mice lacking prostacyclin receptors. Wild-type mice or human volunteers taking cyclooxygenase-2 inhibitors also showed increased plasma ADMA. Endothelial nitric oxide is cardio-protective, reducing thrombosis and atherosclerosis. Consequently, increased ADMA is associated with cardiovascular disease. Thus, our study identifies ADMA as a biomarker and mechanistic bridge between renal cyclooxygenase-2 inhibition and systemic vascular dysfunction with nonsteroidal anti-inflammatory drug usage. Conclusions— We identify the endogenous endothelial nitric oxide synthase inhibitor ADMA as a biomarker and mechanistic bridge between renal cyclooxygenase-2 inhibition and systemic vascular dysfunction. PMID:25492024

  19. Cyclooxygenase-2 prostaglandins mediate anandamide-inhibitory action on nitric oxide synthase activity in the receptive rat uterus.

    PubMed

    Sordelli, Micaela S; Beltrame, Jimena S; Cella, Maximiliano; Franchi, Ana M; Ribeiro, Maria Laura

    2012-06-15

    Anandamide, an endocannabinoid, prostaglandins derived from cyclooxygenase-2 and nitric oxide synthesized by nitric oxide synthase (NOS), are relevant mediators of embryo implantation. We adopted a pharmacological approach to investigate if anandamide modulated NOS activity in the receptive rat uterus and if prostaglandins mediated this effect. As we were interested in studying the changes that occur at the maternal side of the fetal-maternal interface, we worked with uteri obtained from pseudopregnant rats. Females were sacrificed on day 5 of pseudopregnancy, the day in which implantation would occur, and the uterus was obtained. Anandamide (2 ng/kg, i.p.) inhibited NOS activity (P<0.001) and increased the levels of prostaglandin E(2) (P<0.001) and prostaglandin F(2α) (P<0.01). These effects were mediated via cannabinoid receptor type 2, as the pre-treatment with SR144528 (10 mg/kg, i.p.), a selective cannabinoid receptor type 2 antagonist, completely reverted anandamide effect on NOS activity and prostaglandin levels. The pre-treatment with a non-selective cyclooxygenase inhibitor (indomethacin 2.5mg/kg, i.p.) or with selective cyclooxygenase-2 inhibitors (meloxicam 4 mg/kg, celecoxib 3mg/kg, i.p.) reverted anandamide inhibition on NOS, suggesting that prostaglandins are derived from cyclooxygenase-2 mediated anandamide effect. Thus, anandamide levels seemed to modulate NOS activity, fundamental for implantation, via cannabinoid receptor type 2 receptors, in the receptive uterus. This modulation depends on the production of cyclooxygenase-2 derivatives. These data establish cannabinoid receptors and cyclooxygenase enzymes as an interesting target for the treatment of implantation deficiencies. PMID:22554772

  20. Anti-Inflammatory Effects of Specific Cyclooxygenase 2,5-Lipoxygenase, and Inducible Nitric Oxide Synthase Inhibitors on Experimental Autoimmune Anterior Uveitis (EAAU)

    PubMed Central

    Bora, Nalini S.; Sohn, Jeong-Hyeon; Bora, Puran S.; Kaplan, Henry J.; Kulkarni, Prasad

    2007-01-01

    Purpose Inflammation, in general, causes the release of a variety of inflammatory mediators that in turn induce cyclooxygenase (COX) 2, nitric oxide synthase (iNOS) and 5-lipoxygense (LP) synthesis, producing large amounts of inflammatory prostaglandins (PG), nitric oxide (NO), and leukotriene (LT) B4. Therefore, inhibition of these enzymes may abrogate intraocular inflammation in experimental autoimmune anterior uveitis (EAAU). Methods Lewis rats were immunized with melanin-associated antigen (MAA) isolated from bovine iris and ciliary body. These animals were divided into three groups. The first group of rats received subcutaneous injection of COX 2 inhibitor CS 236 at different time points. The second and third groups of animals received subcutaneous aminoguanidine (AG), an iNOS inhibitor, and nordihydroguaiaretic acid (NDGA), a 5-LP inhibitor, respectively. Control animals received vehicle. Rat eyes were examined daily by slit-lamp biomicroscopy from Day 7 to 30 post injection for uveitis. Animals were also sacrificed at various time points for histologic analysis. Results Control animals developed severe EAAU in both eyes. The disease started in these animals on Day 12 post immunization and lasted for ten days. Interestingly, CS 236, a potent COX 2 inhibitor, completely abrogated EAAU when the animals were treated daily from the Day 0 to 14 or Day 0 to 20 after MAA injection. Furthermore, daily CS 236 treatment after the onset of EAAU (Day 14–20) significantly reduced the severity (both clinical and histologic) of EAAU and shortened the duration of disease. iNOS inhibitor (AG) and 5-LP inhibitor (NDGA) partially attenuated EAAU. Conclusions Our results show that EAAU was partially attenuated by AG and NDGA. Interestingly, CS 236, a potent COX 2 inhibitor, completely inhibited EAAU in male Lewis rats most likely by inhibiting the initial phase and onset of the disease. PMID:16019677

  1. First-dose analgesic effect of the cyclo-oxygenase-2 selective inhibitor lumiracoxib in osteoarthritis of the knee: a randomized, double-blind, placebo-controlled comparison with celecoxib [NCT00267215

    PubMed Central

    Wittenberg, Ralf H; Schell, Ernest; Krehan, Gerhard; Maeumbaed, Roland; Runge, Hans; Schlüter, Peter; Fashola, Taiwo OA; Thurston, Helen J; Burger, Klaus J; Trechsel, Ulrich

    2006-01-01

    Cyclo-oxygenase-2 selective inhibitors are frequently used to manage osteoarthritis. We compared the analgesic efficacy of the novel cyclo-oxygenase-2 selective inhibitor lumiracoxib (Prexige®) versus placebo and celecoxib in patients with knee osteoarthritis. This seven day, double-blind, placebo and active comparator controlled, parallel group study included 364 patients aged ≥50 years with moderate-to-severe symptomatic knee osteoarthritis. Patients received lumiracoxib 400 mg/day (four times the recommended chronic dose in osteoarthritis; n = 144), placebo (n = 75), or celecoxib 200 mg twice daily (n = 145). The primary variable was actual pain intensity difference (100 mm visual–analogue scale) between baseline and the mean of three hour and five hour assessments after the first dose. Actual pain intensity difference, average and worst pain, pain relief and functional status (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC™]) were measured over seven days. Patients also completed a global evaluation of treatment effect at study end or premature discontinuation. For the primary variable, the superiority of lumiracoxib versus placebo, the noninferiority of lumiracoxib versus celecoxib, and the superiority of lumiracoxib versus celecoxib were assessed by closed test procedure adjusting for multiplicity, thereby maintaining the overall 5% significance level. In addition, celecoxib was assessed versus placebo in a predefined exploratory manner to assess trial sensitivity. Lumiracoxib provided better analgesia than placebo 3–5 hours after the first dose (P = 0.004) through to study end. The estimated difference between lumiracoxib and celecoxib 3–5 hours after the first dose was not significant (P = 0.185). Celecoxib was not significantly different from placebo in this analysis (P = 0.069). At study end 13.9% of lumiracoxib-treated patients reported complete pain relief versus 5.5% and 5.3% of celecoxib and placebo recipients

  2. 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

    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

    2012-05-29

    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.

  3. SELECTIVE AND NON-SELECTIVE METALLOPROTEINASE INHIBITORS REDUCE IL-1-INDUCED CARTILAGE DEGRADATION AND LOSS OF MECHANICAL PROPERTIES

    PubMed Central

    Wilson, Christopher G.; Palmer, Ashley W.; Zuo, Fengrong; Eugui, Elsie; Wilson, Stacy; Mackenzie, Rebecca; Sandy, John D.; Levenston, Marc E.

    2015-01-01

    Articular cartilage undergoes matrix degradation and loss of mechanical properties when stimulated with proinflammatory cytokines such as interleukin-1 (IL-1). Aggrecanases and matrix metalloproteinases (MMPs) are thought to be principal downstream effectors of cytokine-induced matrix catabolism, and aggrecanase- or MMP-selective inhibitors reduce or block matrix destruction in several model systems. The objective of this study was to use metalloproteinase inhibitors to perturb IL-1-induced matrix catabolism in bovine cartilage explants and examine their effects on changes in tissue compression and shear properties. Explanted tissue was stimulated with IL-1 for up to 24 days in the absence or presence of inhibitors which were aggrecanase-selective, MMP-selective, or non-selective. Analysis of conditioned media and explant digests revealed that aggrecanase-mediated aggrecanolysis was delayed to varying extents with all inhibitor treatments, but that aggrecan release persisted. Collagen degradation was abrogated by MMP- and non-selective inhibitors and reduced by the aggrecanase inhibitor. The inhibitors delayed but did not reduce loss of the equilibrium compression modulus, whereas the loss of dynamic compression and shear moduli was delayed and reduced. The data suggest that non-metalloproteinase mechanisms participate in IL-1-induced matrix degradation and loss of tissue material properties. PMID:17174540

  4. Discovery of a potent cyclooxygenase-2 inhibitor, S4, through docking-based pharmacophore screening, in vivo and in vitro estimations.

    PubMed

    Tseng, Tien-Sheng; Chuang, Show-Mei; Hsiao, Nai-Wan; Chen, Yi-Wen; Lee, Yu-Ching; Lin, Chi-Chen; Huang, Cheng; Tsai, Keng-Chang

    2016-07-19

    Cyclooxygenase (COX; EC: 1.14.99.1), the key enzyme in prostaglandin production in the human body, is a major pharmacological target for developing anti-inflammatory agents. Nonsteroidal anti-inflammatory drugs exhibit anti-inflammatory and analgesic activities when inhibiting COX-2 but cause gastrointestinal toxicity and other side effects because of concurrent inhibition of COX-1. Thus, potent and safe inhibitors against COX-2 are urgently required. We constructed a novel docking-based pharmacophore model for screening selective COX-2 inhibitors and discovered compounds S1, S2, S3, and S4, which apparently inhibit COX-2. Particularly, S4 inhibits COX-2 in vitro and shows a potent anti-inflammatory effect in vivo without cytotoxicity. Molecular docking analyses revealed that S4 interacted satisfactorily with the active site of COX-2 but not with that of COX-1. This reveals that S4 more specifically inhibits COX-2 and has potential for application in developing anti-inflammatory and anticancer agents. PMID:27265567

  5. Regulation of tumorigenic Wnt signaling by cyclooxygenase-2, 5-lipoxygenase and their pharmacological inhibitors: A basis for novel drugs targeting cancer cells?

    PubMed

    Roos, Jessica; Grösch, Sabine; Werz, Oliver; Schröder, Peter; Ziegler, Slava; Fulda, Simone; Paulus, Patrick; Urbschat, Anja; Kühn, Benjamin; Maucher, Isabelle; Fettel, Jasmin; Vorup-Jensen, Thomas; Piesche, Matthias; Matrone, Carmela; Steinhilber, Dieter; Parnham, Michael J; Maier, Thorsten J

    2016-01-01

    Canonical Wnt signaling is a highly conserved pathway with a prominent role in embryogenic development, adult tissue homeostasis, cell polarization, stem cell biology, cell differentiation, and proliferation. Furthermore, canonical Wnt signaling is of pivotal importance in the pathogenesis of a number of cancer types and crucially affects tumor initiation, cancer cell proliferation, cancer cell apoptosis, and metastasis. Reports over the last decade have provided strong evidence for a pathophysiological role of Wnt signaling in non-malignant classical inflammatory and neurodegenerative diseases. Although, several agents suppressing the Wnt pathway at different levels have been identified, the development of clinically relevant Wnt-inhibiting agents remains challenging due to selectivity and toxicity issues. Several studies have shown that long-term administration of non-steroidal anti-inflammatory drugs protects against colon cancer and potentially other tumor types by interfering both with the COX and the Wnt pathway. Our own studies have shown that non-steroidal anti-inflammatory drugs suppress Wnt signaling by targeting the pro-inflammatory enzyme 5-lipoxygenase which is the key enzyme pathophysiologically involved in the synthesis of leukotrienes. Furthermore, we found a direct link between the 5-lipoxygenase and Wnt signaling pathways, which is essential for the maintenance of leukemic stem cells. Accordingly, genetic and pharmacological inhibition of 5-lipoxygenase led to an impairment of Wnt-dependent acute and chronic myeloid leukemic stem cells. We believe that 5-lipoxygenase inhibitors might represent a novel type of Wnt inhibitor activating a potentially naturally occurring novel mechanism of suppression of Wnt signaling that is non-toxic, at least in mice, and is potentially well tolerated in patients. PMID:26549540

  6. Cyclooxygenase-2 inhibitors in ginger (Zingiber officinale)

    PubMed Central

    van Breemen, Richard B.; Tao, Yi; Li, Wenkui

    2010-01-01

    Ginger roots have been used to treat inflammation and have been reported to inhibit cyclooxygenase (COX). Ultrafiltration liquid chromatography mass spectrometry was used to screen a chloroform partition of a methanol extract of ginger roots for COX-2 ligands, and 10-gingerol, 12-gingerol, 8-shogaol, 10-shogaol, 6-gingerdione, 8-gingerdione, 10-gingerdione, 6-dehydro-10-gingerol, 6-paradol, and 8-paradol bound to the enzyme active site. Purified 10-gingerol, 8-shogaol and 10-shogaol inhibited COX-2 with IC50 values of 32 μM, 17.5 μM and 7.5 μM, respectively. No inhibition of COX-1 was detected. Therefore, 10-gingerol, 8-shogaol and 10-shogaol inhibit COX-2 but not COX-1, which can explain, in part, anti-inflammatory properties of ginger. PMID:20837112

  7. Cyclooxygenase-2 in newborn hyperoxic lung injury.

    PubMed

    Britt, Rodney D; Velten, Markus; Tipple, Trent E; Nelin, Leif D; Rogers, Lynette K

    2013-08-01

    Supraphysiological O2 concentrations, mechanical ventilation, and inflammation significantly contribute to the development of bronchopulmonary dysplasia (BPD).Exposure of newborn mice to hyperoxia causes inflammation and impaired alveolarization similar to that seen in infants with BPD.Previously, we demonstrated that pulmonary cyclooxygenase-2 (COX-2) protein expression is increased in hyperoxia-exposed newborn mice.The present studies were designed to define the role of COX-2 in newborn hyperoxic lung injury.We tested the hypothesis that attenuation of COX-2 activity would reduce hyperoxia-induced inflammation and improve alveolarization.Newborn C3H/HeN micewere injected daily with vehicle, aspirin (nonselective COX-2 inhibitor), or celecoxib (selective COX-2 inhibitor) for the first 7 days of life.Additional studies utilized wild-type (C57Bl/6, COX-2(+/+)), heterozygous (COX-2(+/-)), and homozygous (COX-2(-/-)) transgenic mice.Micewere exposed to room air (21% O2) or hyperoxia (85% O2) for 14 days.Aspirin-injected and COX-2(-/-) pups had reduced levels of monocyte chemoattractant protein (MCP-1) in bronchoalveolar lavage fluid (BAL).Both aspirin and celecoxib treatment reduced macrophage numbers in the alveolar walls and air spaces.Aspirin and celecoxib treatment attenuated hyperoxia-induced COX activity, including altered levels of prostaglandin (PG)D2 metabolites.Decreased COX activity, however, did not prevent hyperoxia-induced lung developmental deficits.Our data suggest thatincreased COX-2 activity may contribute to proinflammatory responses, including macrophage chemotaxis, during exposure to hyperoxia.Modulation of COX-2 activity may be a useful therapeutic target to limit hyperoxia-induced inflammation in preterm infants at risk of developing BPD. PMID:23624331

  8. Risk of Bias in Systematic Reviews of Non-Randomized Studies of Adverse Cardiovascular Effects of Thiazolidinediones and Cyclooxygenase-2 Inhibitors: Application of a New Cochrane Risk of Bias Tool

    PubMed Central

    Bilandzic, Anja; Fitzpatrick, Tiffany; Rosella, Laura; Henry, David

    2016-01-01

    Background Systematic reviews of the effects of healthcare interventions frequently include non-randomized studies. These are subject to confounding and a range of other biases that are seldom considered in detail when synthesizing and interpreting the results. Our aims were to assess the reliability and usability of a new Cochrane risk of bias (RoB) tool for non-randomized studies of interventions and to determine whether restricting analysis to studies with low or moderate RoB made a material difference to the results of the reviews. Methods and Findings We selected two systematic reviews of population-based, controlled non-randomized studies of the relationship between the use of thiazolidinediones (TZDs) and cyclooxygenase-2 (COX-2) inhibitors and major cardiovascular events. Two epidemiologists applied the Cochrane RoB tool and made assessments across the seven specified domains of bias for each of 37 component studies. Inter-rater agreement was measured using the weighted Kappa statistic. We grouped studies according to overall RoB and performed statistical pooling for (a) all studies and (b) only studies with low or moderate RoB. Kappa scores across the seven bias domains ranged from 0.50 to 1.0. In the COX-2 inhibitor review, two studies had low overall RoB, 14 had moderate RoB, and five had serious RoB. In the TZD review, six studies had low RoB, four had moderate RoB, four had serious RoB, and two had critical RoB. The pooled odds ratios for myocardial infarction, heart failure, and death for rosiglitazone versus pioglitazone remained significantly elevated when analyses were confined to studies with low or moderate RoB. However, the estimate for myocardial infarction declined from 1.14 (95% CI 1.07–1.24) to 1.06 (95% CI 0.99–1.13) when analysis was confined to studies with low RoB. Estimates of pooled relative risks of cardiovascular events with COX-2 inhibitors compared with no nonsteroidal anti-inflammatory drug changed little when analyses were

  9. Cyclooxygenase-2 and kidney failure.

    PubMed

    Rios, Amelia; Vargas-Robles, Hilda; Gámez-Méndez, Ana Maria; Escalante, Bruno

    2012-08-01

    Cyclooxygenase (COX)-dependent prostaglandins are necessary for normal kidney function. These prostaglandins are associated with inflammation, maintenance of sodium and water homeostasis, control of renin release, renal vasodilation, vasoconstriction attenuation, and prenatal renal development. COX-2 expression is regulated by the renin-angiotensin system, glucocorticoids or mineralcorticoids, and aldosterone, supporting a role for COX-2 in kidney function. Indeed, COX-2 mRNA and protein levels as well as enzyme activity are increased, along with PGE2, during kidney failure. In addition, changes in COX-2 expression are associated with increased blood pressure, urinary volume, sodium and protein and decreased urinary osmolarity. Intrarenal mechanisms such as angiotensin II (Ang II) production, increased sodium delivery, glomerular hypertension, and renal tubular inflammation have been suggested to be responsible for the increase in COX-2 expression. Although, specific COX-2 pharmacological inhibition has been related to the prevention of kidney damage, clinical studies have reported that COX-2 inhibition may cause side effects such as edema or a modest elevation in blood pressure and could possibly interfere with antihypertensive drugs and increase the risk of cardiovascular complications. Thus, administration of COX-2 inhibitors requires caution, especially in the presence of underlying cardiovascular disease. PMID:22119250

  10. Cyclooxygenase-2 inhibition reduces stress-induced affective pathology.

    PubMed

    Gamble-George, Joyonna Carrie; Baldi, Rita; Halladay, Lindsay; Kocharian, Adrina; Hartley, Nolan; Silva, Carolyn Grace; Roberts, Holly; Haymer, Andre; Marnett, Lawrence J; Holmes, Andrew; Patel, Sachin

    2016-01-01

    Mood and anxiety disorders are the most prevalent psychiatric conditions and are exacerbated by stress. Recent studies have suggested cyclooxygenase-2 (COX-2) inhibition could represent a novel treatment approach or augmentation strategy for affective disorders including anxiety disorders and major depression. We show that traditional COX-2 inhibitors and a newly developed substrate-selective COX-2 inhibitor (SSCI) reduce a variety of stress-induced behavioral pathologies in mice. We found that these behavioral effects were associated with a dampening of neuronal excitability in the basolateral amygdala (BLA) ex vivo and in vivo, and were mediated by small-conductance calcium-activated potassium (SK) channel and CB1 cannabinoid receptor activation. Taken together, these data provide further support for the potential utility of SSCIs, as well as traditional COX-2 inhibitors, as novel treatment approaches for stress-related psychiatric disorders. PMID:27162170

  11. Cyclooxygenase-2 inhibition reduces stress-induced affective pathology

    PubMed Central

    Gamble-George, Joyonna Carrie; Baldi, Rita; Halladay, Lindsay; Kocharian, Adrina; Hartley, Nolan; Silva, Carolyn Grace; Roberts, Holly; Haymer, Andre; Marnett, Lawrence J; Holmes, Andrew; Patel, Sachin

    2016-01-01

    Mood and anxiety disorders are the most prevalent psychiatric conditions and are exacerbated by stress. Recent studies have suggested cyclooxygenase-2 (COX-2) inhibition could represent a novel treatment approach or augmentation strategy for affective disorders including anxiety disorders and major depression. We show that traditional COX-2 inhibitors and a newly developed substrate-selective COX-2 inhibitor (SSCI) reduce a variety of stress-induced behavioral pathologies in mice. We found that these behavioral effects were associated with a dampening of neuronal excitability in the basolateral amygdala (BLA) ex vivo and in vivo, and were mediated by small-conductance calcium-activated potassium (SK) channel and CB1 cannabinoid receptor activation. Taken together, these data provide further support for the potential utility of SSCIs, as well as traditional COX-2 inhibitors, as novel treatment approaches for stress-related psychiatric disorders. DOI: http://dx.doi.org/10.7554/eLife.14137.001 PMID:27162170

  12. Development of a potent and selective FLT3 kinase inhibitor by systematic expansion of a non-selective fragment-screening hit.

    PubMed

    Nakano, Hirofumi; Hasegawa, Tsukasa; Imamura, Riyo; Saito, Nae; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo

    2016-05-01

    A non-selective inhibitor (1) of FMS-like tyrosine kinase-3 (FLT3) was identified by fragment screening and systematically modified to afford a potent and selective inhibitor 26. We confirmed that 26 inhibited the growth of FLT-3-activated human acute myeloid leukemia cell line MV4-11. Our design strategy enabled rapid development of a novel type of FLT3 inhibitor from the hit fragment in the absence of target-structural information. PMID:26995531

  13. Selective Visualization of Cyclooxygenase-2 in Inflammation and Cancer by Targeted Fluorescent Imaging Agents†

    PubMed Central

    Uddin, Md. Jashim; Crews, Brenda C.; Blobaum, Anna L.; Kingsley, Philip J.; Gorden, D. Lee; McIntyre, J. Oliver; Matrisian, Lynn M.; Subbaramaiah, Kotha; Dannenberg, Andrew J.; Piston, David W.; Marnett, Lawrence J.

    2010-01-01

    Effective diagnosis of inflammation and cancer by molecular imaging is challenging because of interference from non-selective accumulation of the contrast agents in normal tissues. Here we report a series of novel fluorescence imaging agents that efficiently target cyclooxygenase-2 (COX-2), which is normally absent from cells, but is found at high levels in inflammatory lesions, and in many premalignant and malignant tumors. After either intraperitoneal or intravenous injection, these reagents become highly enriched in inflamed or tumor tissue compared to normal tissue and this accumulation provides sufficient signal for in vivo fluorescence imaging. Further, we show that only the intact parent compound is found in the region of interest. COX-2-specific delivery was unambiguously confirmed using animals bearing targeted deletions of COX-2 and by blocking the COX-2 active site with high affinity inhibitors in both in vitro and in vivo models. Because of their high specificity, contrast, and detectability, these COX-2 beacons are ideal candidates for detection of inflammatory lesions or early-stage COX-2-expressing human cancers, such as those in the esophagus, oropharynx, and colon. PMID:20430759

  14. Synthesis and crystal structure of N-[(dimethylamino)methylidene]-4-[1-(4-nitrophenyl)-1H-tetrazol-5-yl]-benzenesulfonamide: Molecular docking and bioassay studies as cyclooxygenase-2 inhibitor

    NASA Astrophysics Data System (ADS)

    Jawabrah Al-Hourani, Baker; El-Barghouthi, Musa I.; McDonald, Robert; Al-Awaida, Wajdy; Sharma, Sai Kiran; Wuest, Frank

    2016-09-01

    The synthesis of N-[(dimethylamino)methylidene]-4-[1-(4-nitrophenyl)-1H-tetrazol-5-yl]benzenesulfonamide (3) has been easily approached and the structure has been determined by X-ray crystallography. Tetrazole 3 crystallizes in the monoclinic space group C2/c, with the cell parameters determined as a = 35.5408 (18) Å, b = 7.6972 (4) Å, c = 13.0700 (7) Å3, β = 96.8598 (6)°, V = 3549.9 (3) Å3, and Z = 8. Its structure refines to R1 = 0.0341 (for 2986 observed reflections [I ≥ 2σ(I)]) and wR2 = 0.0990 (for all 3637 unique reflections). The aryl rings at the 1- and 5-positions show no conjugation to the tetrazole group, and the [(Dimethylamino)methylene]aminosulfonyl (Me2NCHNSO2) group is disordered, with the two disorder conformers being related by a pseudo mirror plane. In the crystal, intermolecular interactions between adjacent molecule of 3 are dominated by weak (2.4-2.7 Å) CeH…O and CeH…N hydrogen bonds. The molecular docking studies were carried out to understand the interaction of compound 3 within the active site of the cyclooxygenase-2 enzyme, followed by a comparison study with the celecoxib drug as a reference compound. The in vitro bioassay studies of tetrazole 3 toward cyclooxygenase-1 and cyclooxygenase-2 enzymes showed that compound 3 has no inhibition potency for either enzyme.

  15. A Revised Mechanism for Human Cyclooxygenase-2.

    PubMed

    Liu, Yi; Roth, Justine P

    2016-01-01

    The mechanism of ω-6 polyunsaturated fatty acid oxidation by wild-type cyclooxygenase 2 and the Y334F variant, lacking a conserved hydrogen bond to the catalytic tyrosyl radical/tyrosine, was examined for the first time under physiologically relevant conditions. The enzymes show apparent bimolecular rate constants and deuterium kinetic isotope effects that increase in proportion to co-substrate concentrations before converging to limiting values. The trends exclude multiple dioxygenase mechanisms as well as the proposal that initial hydrogen atom abstraction from the fatty acid is the first irreversible step in catalysis. Temperature dependent kinetic studies reinforce the novel finding that hydrogen transfer from the reduced catalytic tyrosine to a terminal peroxyl radical is the first irreversible step that controls regio- and stereospecific product formation. PMID:26565028

  16. Role of cyclooxygenase-2 in intestinal injury in neonatal rats

    PubMed Central

    LU, HUI; ZHU, BING

    2014-01-01

    Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in premature neonates. The pathogenesis of NEC remains poorly understood. The present study aimed to investigate the dynamic change and role of cyclooxygenase-2 (COX-2) in neonatal rats with intestinal injury. Wistar rats, <24 h in age, received an intraperitoneal injection with 5 mg/kg lipopolysaccharide (LPS). Ileal tissues were collected at 1, 3, 6, 12 and 24 h following the LPS challenge for histological evaluation of NEC and for measurements of COX-2 mRNA. The correlation between the degree of intestinal injury and expression of COX-2 mRNA was determined. The LPS-injected pups showed a significant increase in injury scores compared to the control, and the most deteriorating change was at 12 h. COX-2 mRNA expression was upregulated following LPS injection. There was a significantly positive correlation between COX-2 mRNA and the grade of intestinal injury within 12 h, whereas COX-2 mRNA expression had a significantly negative correlation with the severity of intestinal injury at 24 h. COX-2 plays an important role in LPS-induced intestinal injury and the repair processes. Caution should be exerted concerning the potential therapeutic uses of COX-2 inhibitors or promoters in NEC. PMID:25279162

  17. Cost-effectiveness analysis for joint pain treatment in patients with osteoarthritis treated at the Instituto Mexicano del Seguro Social (IMSS): Comparison of nonsteroidal anti-inflammatory drugs (NSAIDs) vs. cyclooxygenase-2 selective inhibitors

    PubMed Central

    Contreras-Hernández, Iris; Mould-Quevedo, Joaquín F; Torres-González, Rubén; Goycochea-Robles, María Victoria; Pacheco-Domínguez, Reyna Lizette; Sánchez-García, Sergio; Mejía-Aranguré, Juan Manuel; Garduño-Espinosa, Juan

    2008-01-01

    Background Osteoarthritis (OA) is one of the main causes of disability worldwide, especially in persons >55 years of age. Currently, controversy remains about the best therapeutic alternative for this disease when evaluated from a cost-effectiveness viewpoint. For Social Security Institutions in developing countries, it is very important to assess what drugs may decrease the subsequent use of medical care resources, considering their adverse events that are known to have a significant increase in medical care costs of patients with OA. Three treatment alternatives were compared: celecoxib (200 mg twice daily), non-selective NSAIDs (naproxen, 500 mg twice daily; diclofenac, 100 mg twice daily; and piroxicam, 20 mg/day) and acetaminophen, 1000 mg twice daily. The aim of this study was to identify the most cost-effective first-choice pharmacological treatment for the control of joint pain secondary to OA in patients treated at the Instituto Mexicano del Seguro Social (IMSS). Methods A cost-effectiveness assessment was carried out. A systematic review of the literature was performed to obtain transition probabilities. In order to evaluate analysis robustness, one-way and probabilistic sensitivity analyses were conducted. Estimations were done for a 6-month period. Results Treatment demonstrating the best cost-effectiveness results [lowest cost-effectiveness ratio $17.5 pesos/patient ($1.75 USD)] was celecoxib. According to the one-way sensitivity analysis, celecoxib would need to markedly decrease its effectiveness in order for it to not be the optimal treatment option. In the probabilistic analysis, both in the construction of the acceptability curves and in the estimation of net economic benefits, the most cost-effective option was celecoxib. Conclusion From a Mexican institutional perspective and probably in other Social Security Institutions in similar developing countries, the most cost-effective option for treatment of knee and/or hip OA would be celecoxib. PMID

  18. Breast cancer--new aspects of tumor biology: are calcitriol and cyclooxygenase-2 possible targets for breast cancer?

    PubMed

    Thill, M; Terjung, A; Friedrich, M

    2014-01-01

    Up until now there have been many advances in treatment options for breast cancers such as targeted therapies like monoclonal antibodies, tyrosine kinase inhibitors, mTOR antagonists, and vaccines. Despite these advances, there are still many more that warrant further exploration. Two of these targets might be the cyclooxygenase-2 (COX-2), the key enzyme required to convert arachidonic acid to prostaglandins, and calcitriol [1,25(OH)2D3] which is the biologically active form of vitamin D. Both calcitriol and the inhibition of COX-2 have shown antiproliferative and prodifferentiation, as well as pro-apoptotic effects in different malignancies in vitro and in vivo, and the key prostaglandin catabolic enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is known to have tumor suppressor activity. Furthermore, the combination ofcalcitriol and nonsteroidal anti-inflammatory drugs (NSAIDs), such as non-selective and selective COX-2 inhibitors, acting synergistically to achieve significant cell growth inhibition in prostate cancer. Some epidemiological studies suggest that vitamin D confers a moderate benefit against breast cancer while most epidemiological studies presume that NSAIDs confer the same. Nevertheless there is growing body of evidence that COX-2 expression is a fundamental step in breast cancer carcinogenesis. To date, clinical trials have been conducted in patients with different malignancies using treatment strategies including COX-2 inhibitors and calcitriol and are showing partially encouraging results. The goal of this review is to shed light on the association between the prostaglandin as well as vitamin D metabolism relating to the incidence and therapy of breast cancers. Moreover, this review will also highlight potential treatment options, as well as extract any existing interactions between the two metabolisms. PMID:25118473

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

    PubMed Central

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

    2016-01-01

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

  20. Inhibition of cyclo-oxygenase-2 exacerbates ischaemia-induced acute myocardial dysfunction in the rabbit

    PubMed Central

    Rossoni, Giuseppe; Muscara, Marcelo N; Cirino, Giuseppe; Wallace, John L

    2002-01-01

    The effects of treatment with a number of cyclo-oxygenase inhibitors, (celecoxib, meloxicam, DuP-697 and aspirin) on ischaemia-reperfusion-induced myocardial dysfunction were examined using an in vitro perfused rabbit heart model.Ischaemia resulted in myocardial dysfunction, as indicated by a significant increase in left ventricular end diastolic pressure and marked changes in coronary perfusion pressure and left ventricular developed pressure. In the post-ischaemic state, coronary perfusion pressure increased dramatically, left ventricular developed pressure recovered to a small degree and there were significant increases in creatinine kinase release (indicative of myocardial damage) and prostacyclin release.Pretreatment with aspirin, or with drugs that selectively inhibit cyclo-oxygenase-2 (celecoxib, meloxicam and DuP-697), resulted in a concentration-dependent exacerbation of the myocardial dysfunction and damage. Exacerbation of myocardial dysfunction and damage was evident with 10 μM concentrations of the cyclo-oxygenase-2 inhibitors, which inhibited prostacyclin release but did not affect cyclo-oxygenase-1 activity (as measured by whole blood thromboxane synthesis).NCX-4016, a nitric oxide-releasing aspirin derivative, significantly reduced the myocardial dysfunction and damage caused by ischaemia and reperfusion. Beneficial effects were observed even at a concentration (100 μM) that significantly inhibited prostacyclin synthesis by the heart.The results suggest that prostacyclin released by cardiac tissue in response to ischaemia and reperfusion is derived, at least in part, from cyclo-oxygenase-2. Cyclo-oxygenase-2 plays an important protective role in a setting of ischaemia-reperfusion of the heart. PMID:11906968

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

    PubMed

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

    2016-09-01

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

  2. Selective Cyclooxygenase-2 Inhibition Protects Against Myocardial Damage in Experimental Acute Ischemia

    PubMed Central

    Carnieto, Alberto; Dourado, Paulo Magno Martins; da Luz, Protásio Lemos; Chagas, Antonio Carlos Palandri

    2009-01-01

    BACKGROUND Acute myocardial infarction is associated with tissue inflammation. Early coronary reperfusion clearly improves the outcome but may help propagate the inflammatory response and enhance tissue damage. Cyclooxygenase-2 is an enzyme that catalyzes the initial step in the formation of inflammatory prostaglandins from arachidonic acid. Cyclooxygenase-2 levels are increased when ischemic cardiac events occur. The overall function of COX-2 in the inflammatory process generated by myocardial ischemic damage has not yet been elucidated. GOAL The objective of this study was to determine whether a selective cyclooxygenase-2 inhibitor (rofecoxib) could alter the evolution of acute myocardial infarction after reperfusion. METHODS AND RESULTS This study was performed with 48 mongrel dogs divided into two groups: controls and those treated with the drug. All animals were prepared for left anterior descending coronary artery occlusion. The dogs then underwent 180 minutes of coronary occlusion, followed by 30 minutes of reperfusion. Blood samples were collected from the venous sinus immediately before coronary occlusion and after 30 minutes of reperfusion for measurements of CPK-MB, CPK-MBm and troponin I. During the experiment we observed the mean blood pressure, heart rate and coronary flow. The coronary flow and heart rate did not change, but in the control group, there was blood pressure instability, in addition to maximal levels of CPK-MB post-infarction. The same results were observed for CPK-MBm and troponin I. CONCLUSION In a canine model of myocardial ischemia-reperfusion, selective inhibition of Cyclooxygenase-2 with rofecoxib was not associated with early detrimental effects on the hemodynamic profile or the gross extent of infarction; in fact, it may be beneficial by limiting cell necrosis. PMID:19330252

  3. Crystallization of recombinant cyclo-oxygenase-2

    NASA Astrophysics Data System (ADS)

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

    1999-01-01

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

  4. Exploring the Molecular Determinants of Substrate-Selective Inhibition of Cyclooxygenase-2 by Lumiracoxib

    PubMed Central

    Windsor, Matthew A.; Valk, Pieter L.; Xu, Shu; Banerjee, Surajit; Marnett, Lawrence J.

    2013-01-01

    Lumiracoxib is a substrate-selective inhibitor of endocannabinoid oxygenation by cyclooxygenase-2 (COX-2). We assayed a series of lumiracoxib derivatives to identify the structural determinants of substrate-selective inhibition. The hydrogen-bonding potential of the substituents at the ortho positions of the aniline ring dictated the potency and substrate selectivity of the inhibitors. The presence of a 5’-methyl group on the phenylacetic acid ring increased the potency of molecules with a single ortho substituent. Des-fluorolumiracoxib (2) was the most potent and selective inhibitor of endocannabinoid oxygenation. The positioning of critical substituents in the binding site was identified from a 2.35 Å crystal structure of lumiracoxib bound to COX-2. PMID:24060487

  5. Cyclooxygenase-2 Inhibition Attenuates Abdominal Aortic Aneurysm Progression in Hyperlipidemic Mice

    PubMed Central

    Ghoshal, Sarbani; Loftin, Charles D.

    2012-01-01

    Abdominal aortic aneurysms (AAAs) are a chronic inflammatory disease that increase the risk of life-threatening aortic rupture. In humans, AAAs have been characterized by increased expression of cyclooxygenase-2 and the inactivation of COX-2 prior to disease initiation reduces AAA incidence in a mouse model of the disease. The current study examined the effectiveness of selective cyclooxygenase-2 (COX-2) inhibition on reducing AAA progression when administered after the initiation of AAA formation. AAAs were induced in hyperlipidemic apolipoprotein E-deficient mice by chronic angiotensin II (AngII) infusion and the effect of treatment with the COX-2 inhibitor celecoxib was examined when initiated at different stages of the disease. Celecoxib treatment that was started 1 week after initiating AngII infusion reduced AAA incidence by 61% and significantly decreased AAA severity. Mice treated with celecoxib also showed significantly reduced aortic rupture and mortality. Treatment with celecoxib that was started at a late stage of AAA development also significantly reduced AAA incidence and severity. Celecoxib treatment significantly increased smooth muscle alpha-actin expression in the abdominal aorta and did not reduce expression of markers of macrophage-dependent inflammation. These findings indicate that COX-2 inhibitor treatment initiated after formation of AngII-induced AAAs effectively reduces progression of the disease in hyperlipidemic mice. PMID:23209546

  6. Mechanism underlying the reversal of contractility dysfunction in experimental colitis by cyclooxygenase-2 inhibition.

    PubMed

    Khan, I; Oriowo, M A

    2006-03-01

    Inflammatory bowel diseases are associated with reduced colonic contractility and induction of cyclooxygenase-2. In this study a possible role of cyclooxygenase-2 in and the underlying mechanism of the reduced contractility were investigated in experimental colitis. The effects of meloxicam, a cyclooxygenase-2 selective inhibitor were examined on colonic contractility and MAP kinase p38 and ERK(1/2) expression. Colitis was induced in Sprague-Dawley male rats by intra-colonic instillation of trinitrobenzenesulphonic acid (TNBS; 40 mg/rat in 50 ethanol). The animals were divided into three groups. Group 1 (n=9) received meloxicam (3 mg/kg-day) gavage 1 h before and 1 day (Group 2) after induction of colitis. Group 3 (n=9) received phosphate buffered saline (PBS) in a similar manner and served as colitic control. The non colitic control animals received meloxicam in a similar manner. The animals were sacrificed after 5 days of treatment, colon was cleaned with PBS and colonic smooth muscle was obtained which was used in this study. Meloxicam treatment given 1 h before or 1 day after administration of colitis restored the reduced colonic contractility without affecting the sensitivity to carbachol. The levels of colonic smooth muscle IL-1beta mRNA, PGE(2), ERK(1/2), p38, malondialdehyde, myeloperoxidase activity and colonic mass were increased, whereas the body weight was decreased due to TNBS. The changes except colonic muscle mass and p38 expression were reversed by meloxicam treatment. These findings indicate that restoration of reduced colonic contractility by meloxicam is mediated by ERK(1/2), and that ERK(1/2) may serve as an important anti inflammatory target for treatment of colitis. PMID:16835710

  7. Diosgenin, a plant steroid, induces apoptosis in human rheumatoid arthritis synoviocytes with cyclooxygenase-2 overexpression

    PubMed Central

    Liagre, Bertrand; Vergne-Salle, Pascale; Corbiere, Cecile; Charissoux, Jean L; Beneytout, Jean L

    2004-01-01

    In the present study, we have shown for the first time that a plant steroid, diosgenin, causes an inhibition of the growth of fibroblast-like synoviocytes from human rheumatoid arthritis, with apoptosis induction associated with cyclooxygenase-2 (COX-2) up-regulation. Celecoxib, a selective COX-2 inhibitor, provoked a large decrease in diosgenin-induced apoptosis even in the presence of exogenous prostaglandin E2, whereas interleukin-1β, a COX-2 inducer, strongly increased diosgenin-induced apoptosis of these synoviocytes. These findings suggest that the proapoptotic effect of diosgenin is associated with overexpression of COX-2 correlated with overproduction of endogenous prostaglandin E2. We also observed a loss of mitochondrial membrane potential, caspase-3 activation, and DNA fragmentation after diosgenin treatment. PMID:15225373

  8. Inhibition of cyclooxygenase 2 in mice increases production of g-csf and induces radioprotection.

    PubMed

    Hofer, M; Pospísil, M; Holá, J; Vacek, A; Streitová, D; Znojil, V

    2008-11-01

    Meloxicam, a selective inhibitor of cyclooxygenase 2, was tested to determine its ability to modulate hematopoiesis and to influence survival of mid-lethally gamma-irradiated mice. A single dose of meloxicam (20 mg/kg) administered to mice intraperitoneally 1 h before irradiation was shown to enhance serum levels of granulocyte colony-stimulating factor (G-CSF) during the first 24 h after irradiation, to elevate numbers of granulocytic precursor cells in bone marrow and granulocyte counts in peripheral blood on day 10 after irradiation, and to increase 30-day survival of these mice. The results provide new evidence for the protective ability of meloxicam administration to mice irradiated with mid-lethal doses and contribute to the understanding of the mechanisms of this meloxicam action by drawing attention to the possible role of increased endogenous G-CSF production. PMID:18959461

  9. Cyclooxygenase-2 (COX-2) expression in canine intracranial meningiomas.

    PubMed

    Rossmeisl, J H; Robertson, J L; Zimmerman, K L; Higgins, M A; Geiger, D A

    2009-09-01

    Meningiomas are the most common canine intracranial tumour. Neurologic disability and death from treatment failure remain problematic despite current surgical and radiotherapeutic treatments for canine intracranial meningiomas. Cyclooxygenase-2 (COX-2) over-expression has been demonstrated in multiple canine malignancies, and COX-2 inhibitory treatment strategies have been shown to have both preventative and therapeutic effects in spontaneous and experimental models of cancer. The purpose of this study was to evaluate COX-2 expression in canine intracranial meningiomas. Immunohistochemical and Western blot (WB) analyses showed COX-2 expression in multiple tissues of the normal canine brain, and 87% (21/24) of intracranial meningiomas studied were immunoreactive to COX-2. No significant associations between COX-2 immunoreactivity and tumour grade were identified. Further studies are required to elucidate the physiologic roles of constitutive COX-2 expression in the central nervous system as well as its participation in meningioma tumourigenesis. PMID:19691646

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

    PubMed Central

    Temml, Veronika; Maghradze, David; Vanek, Tomas

    2014-01-01

    Cyclooxygenases and lipoxygenases are proinflammatory enzymes; the former affects platelet aggregation, vasoconstriction, vasodilatation and later the development of atherosclerosis. Red wines from Georgia and central and western Europe inhibited cyclooxygenase-1 (COX-1) activity in the range of 63–94%, cyclooxygenase-2 (COX-2) activity in the range of 20–44% (tested at a concentration of 5 mL/L), and 5-lipoxygenase (5-LOX) activity in the range of 72–84% (at a concentration of 18.87 mL/L). White wines inhibited 5-LOX in the range of 41–68% at a concentration of 18.87 mL/L and did not inhibit COX-1 and COX-2. Piceatannol (IC50 = 0.76 μM) was identified as a strong inhibitor of 5-LOX followed by luteolin (IC50 = 2.25 μM), quercetin (IC50 = 3.29 μM), and myricetin (IC50 = 4.02 μM). trans-Resveratrol was identified as an inhibitor of COX-1 (IC50 = 2.27 μM) and COX-2 (IC50 = 3.40 μM). Red wine as a complex mixture is a powerful inhibitor of COX-1, COX-2, and 5-LOX, the enzymes involved in eicosanoid biosynthetic pathway. PMID:24976682

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

    PubMed Central

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

    1994-01-01

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

  12. Cyclooxygenase-2 and the inflammogenesis of breast cancer

    PubMed Central

    Harris, Randall E; Casto, Bruce C; Harris, Zachary M

    2014-01-01

    Cohesive scientific evidence from molecular, animal, and human investigations supports the hypothesis that constitutive overexpression of cyclooxygenase-2 (COX-2) is a ubiquitous driver of mammary carcinogenesis, and reciprocally, that COX-2 blockade has strong potential for breast cancer prevention and therapy. Key findings include the following: (1) COX-2 is constitutively expressed throughout breast cancer development and expression intensifies with stage at detection, cancer progression and metastasis; (2) essential features of mammary carcinogenesis (mutagenesis, mitogenesis, angiogenesis, reduced apoptosis, metastasis and immunosuppression) are linked to COX-2-driven prostaglandin E2 (PGE-2) biosynthesis; (3) upregulation of COX-2 and PGE-2 expression induces transcription of CYP-19 and aromatase-catalyzed estrogen biosynthesis which stimulates unbridled mitogenesis; (4) extrahepatic CYP-1B1 in mammary adipose tissue converts paracrine estrogen to carcinogenic quinones with mutagenic impact; and (5) agents that inhibit COX-2 reduce the risk of breast cancer in women without disease and reduce recurrence risk and mortality in women with breast cancer. Recent sharp increases in global breast cancer incidence and mortality are likely driven by chronic inflammation of mammary adipose and upregulation of COX-2 associated with the obesity pandemic. The totality of evidence clearly supports the supposition that mammary carcinogenesis often evolves as a progressive series of highly specific cellular and molecular changes in response to induction of constitutive over-expression of COX-2 and the prostaglandin cascade in the “inflammogenesis of breast cancer”. PMID:25302170

  13. Role of cyclooxygenase-2 in gastric cancer development and progression

    PubMed Central

    Cheng, Jian; Fan, Xiao-Ming

    2013-01-01

    Although the incidence of gastric cancer has been declining in recent decades, it remains a major public health issue as the second leading cause of cancer death worldwide. In China, gastric cancer is still the main cause of death in patients with malignant tumors. Most patients are diagnosed at an advanced stage and mortality is high. Cyclooxygenase-2 (COX-2) is a rate-limiting enzyme in prostanoid synthesis and plays an important role in the development and progression of gastric cancer. The expression of COX-2 in gastric cancer is upregulated and its molecular mechanisms have been investigated. Helicobacter pylori infection, tumor suppressor gene mutation and the activation of nuclear factor-kappa B may be responsible for the elevated expression of COX-2 in gastric cancer. The mechanisms of COX-2 in the development and progression of gastric cancer are probably through promoting the proliferation of gastric cancer cells, while inhibiting apoptosis, assisting angiogenesis and lymphatic metastasis, and participating in cancer invasion and immunosuppression. This review is intended to discuss, comment and summarize recent research progress on the role of COX-2 in gastric cancer development and progression, and elucidate the molecular mechanisms which might be involved in the carcinogenesis. PMID:24259966

  14. Mammalian Target of Rapamycin Complex 1 and Cyclooxygenase 2 Pathways Cooperatively Exacerbate Endometrial Cancer

    PubMed Central

    Daikoku, Takiko; Terakawa, Jumpei; Hossain, Md M.; Yoshie, Mikihiro; Cappelletti, Monica; Yang, Peiying; Ellenson, Lora H.; Dey, Sudhansu K.

    2015-01-01

    The underlying causes of endometrial cancer (EMC) are poorly understood, and treatment options for patients with advanced stages of the disease are limited. Mutations in the phosphatase and tensin homologue gene are frequently detected in EMC. Cyclooxygenase 2 (Cox2) and mammalian target of rapamycin complex 1 (mTORC1) are known downstream targets of the phosphatase and tensin homologue protein, and their activities are up-regulated in EMC. However, it is not clear whether Cox2 and mTORC1 are crucial players in cancer progression or whether they work in parallel or cooperatively. In this study, we used a Cox2 inhibitor, celecoxib, and an mTORC1 inhibitor, rapamycin, in mouse models of EMC and in human EMC cell lines to explore the interactive roles of Cox2 and mTORC1 signaling. We found that a combined treatment with celecoxib and rapamycin markedly reduces EMC progression. We also observed that rapamycin reduces Cox2 expression, whereas celecoxib reduces mTORC1 activity. These results suggest that Cox2 and mTORC1 signaling is cross-regulated and cooperatively exacerbate EMC. PMID:25058027

  15. Cobalt Protoporphyrin Upregulates Cyclooxygenase-2 Expression Through a Heme Oxygenase-Independent Mechanism.

    PubMed

    Lin, Hsiao-Yun; Tsai, Chon-Haw; Lin, Chingju; Yeh, Wei-Lan; Tsai, Cheng-Fang; Chang, Pei-Chun; Wu, Ling-Hsuan; Lu, Dah-Yuu

    2016-09-01

    Cobalt protoporphyrin (CoPP) is a potent HO-1 inducer and generally known to be an antioxidant in various cell types. Little is known about the CoPP-induced cyclooxygenase-2 (COX-2) expression and its downstream signaling in microglial cells. In current study, CoPP caused concentration- and time-dependent increases in COX-2 expression in microglial cells. Furthermore, activation of apoptosis signal-regulating kinase (ASK) 1/MAP kinase involved in CoPP-induced COX-2 expression in microglia. CoPP also induced P2X7 receptor activation, and treatment of P2X7 inhibitors effectively reduced CoPP-induced COX-2 expression. Protein inhibitor of activated STAT (PIAS) 1 is reported to be involved in modulating anti-inflammatory response through negative regulation of transcription factors. Interestingly, treatment with CoPP markedly induced PIAS1 degradation which is regulated by PI3K, Akt, and glycogen synthase kinase 3α/β (GSK3α/β) signaling pathways. These results suggest that CoPP induces COX-2 expression through activating P2X7 receptors and ASK1/MAP kinases as well as PIAS1 degradation signaling pathways. Our study provides a new insight into the regulatory effect of CoPP on neuroinflammation in microglial cells. PMID:26255181

  16. Inhibition of cyclooxygenase-2 by NS398 attenuates noise-induced hearing loss in mice

    PubMed Central

    Sun, Yu; Yu, Jintao; Lin, Xi; Tang, Wenxue

    2016-01-01

    Noise-induced hearing loss (NIHL) is an important occupational disorder. However, the molecular mechanisms underlying NIHL have not been fully clarified; therefore, the condition lacks effective therapeutic methods. Cyclooxygenase-2 (Cox-2) is an inducible enzyme involved in the synthesis of prostaglandins, and has been implicated in many pathophysiological events, such as oxidative stress and inflammation. In this study, we investigated the possible role of Cox-2 in the mechanisms of NIHL and the therapeutic effect of the Cox-2 inhibitor NS398 on NIHL using a mouse model. We demonstrated that Cox-2 is constitutively expressed in the mouse cochlea, and its expression could be dramatically up-regulated by high levels of noise exposure. Furthermore, we demonstrated that pre-treatment with the Cox-2 inhibitor NS398 could inhibit Cox-2 expression during noise overstimulation; and could attenuate noise-induced hearing loss and hair cell damage. Our results suggest that Cox-2 is involved in the pathogenesis of NIHL; and pharmacological inhibition of Cox-2 has considerable therapeutic potential in NIHL. PMID:26934825

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

    PubMed

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

    2016-06-01

    Cyclooxygenase-2 (COX-2) is expressed in virtually all solid tumors and its overexpression is a hallmark of inflammation. Thus, it is a potentially powerful biomarker for the early clinical detection of inflammatory disease and human cancers. We report a reactive oxygen species (ROS) responsive micellar nanoparticle, PPS-b-POEGA, that solubilizes the first fluorescent COX-2-selective inhibitor fluorocoxib A (FA) for COX-2 visualization in vivo. Pharmacokinetics and biodistribution of FA-PPS-b-POEGA nanoparticles (FA-NPs) were assessed after a fully-aqueous intravenous (i.v.) administration in wild-type mice and revealed 4-8 h post-injection as an optimal fluorescent imaging window. Carrageenan-induced inflammation in the rat and mouse footpads and 1483 HNSCC tumor xenografts were successfully visualized by FA-NPs with fluorescence up to 10-fold higher than that of normal tissues. The targeted binding of the FA cargo was blocked by pretreatment with the COX-2 inhibitor indomethacin, confirming COX-2-specific binding and local retention of FA at pathological sites. Our collective data indicate that FA-NPs are the first i.v.-ready FA formulation, provide high signal-to-noise in inflamed, premalignant, and malignant tissues, and will uniquely enable clinical translation of the poorly water-soluble FA compound. PMID:27043768

  18. Cyclooxygenase-2 inhibition attenuates hypoxic cancer cells induced m2-polarization of macrophages.

    PubMed

    Dubey, P; Shrivastava, R; Tripathi, C; Jain, N K; Tewari, B N; Lone, M-U-D; Baghel, K S; Kumar, V; Misra, S; Bhadauria, S; Bhatt, M L B

    2014-01-01

    Tumor-associated macrophages (TAMs), represent a major subpopulation of tumor infiltrating immune cells. These alternatively activated M2-polarized macrophages are well known for their pro-tumor functions. Owing to their established role in potentiating tumor-neovasculogenesis and metastasis, TAMs have emerged as promising target for anti-cancer immunotherapy. One of the key TAMs related phenomenon that is amenable to therapeutic intervention is their phenotype switching into alternatively activated M2-polarized macrophages. Hindering macrophage polarization towards a pro-tumor M2 phenotype, or better still reprogramming the M2 like TAMs towards M1 subtype is being considered a beneficial anti-cancer strategy. Hypoxic tumor milieu has been proposed as one of the most plausible factor governing M2-polarization of macrophages. We recently demonstrated that hypoxic tumor cells imparted a pro—angiogenic M2 skewed phenotype to macrophages. Furthermore, sizeable body of data indicates for participation of cyclooxygenase-2 (COX-2) in macrophage polarization. Concordantly, inhibition of COX-2 is associated with impaired macrophage polarization. Prompted by this in the current study we decided to explore if inhibition of COX-2 activity via chemical inhibitors may prevent hypoxic cancer cell induced M2-polarization of macrophages. We observed that treatment with Flunixin meglumine, an established preferential inhibitor of COX-2 activity markedly inhibited hypoxic cancer cell induced of M2-polarization of macrophages thereby indicating for usage of COX-2 inhibition as possible anti-cancer treatment modality. PMID:25210855

  19. Cyclooxygenase-2 Mediates Anandamide Metabolism in the Mouse Brain

    PubMed Central

    Kaczocha, Martin

    2010-01-01

    Cyclooxygenase-2 (COX-2) mediates inflammation and contributes to neurodegeneration. Best known for its pathological up-regulation, COX-2 is also constitutively expressed within the brain and mediates synaptic transmission through prostaglandin synthesis. Along with arachidonic acid, COX-2 oxygenates the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol in vitro. Inhibition of COX-2 enhances retrograde signaling in the hippocampus, suggesting COX-2 mediates endocannabinoid tone in healthy brain. The degree to which COX-2 may regulate endocannabinoid metabolism in vivo is currently unclear. Therefore, we explored the effect of COX-2 inhibition on [3H]AEA metabolism in mouse brain. Although AEA is hydrolyzed primarily by fatty acid amide hydrolase (FAAH), ex vivo autoradiography revealed that COX-2 inhibition by nimesulide redirected [3H]AEA substrate from COX-2 to FAAH in the cortex, hippocampus, thalamus, and periaqueductal gray. These data indicate that COX-2 possesses the capacity to metabolize AEA in vivo and can compete with FAAH for AEA in several brain regions. Temporal fluctuations in COX-2 expression were observed in the brain, with an increase in COX-2 protein and mRNA in the hippocampus at midnight compared with noon. COX-2 immunolocalization was robust in the hippocampus and several cortical regions. Although most regions exhibited no temporal changes in COX-2 immunolocalization, increased numbers of immunoreactive cells were detected at midnight in layers II and III of the somatosensory and visual cortices. These temporal variations in COX-2 distribution reduced the enzyme's contribution toward [3H]AEA metabolism in the somatosensory cortex at midnight. Taken together, our findings establish COX-2 as a mediator of regional AEA metabolism in mouse brain. PMID:20702753

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

    PubMed Central

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

    2015-01-01

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

  1. Inhibition of cyclooxygenase-2 prevents intra-abdominal adhesions by decreasing activity of peritoneal fibroblasts

    PubMed Central

    Wei, Guangbing; Chen, Xin; Wang, Guanghui; Jia, Pengbo; Xu, Qinhong; Ping, Gaofeng; Wang, Kang; Li, Xuqi

    2015-01-01

    Background Postoperative intra-abdominal adhesions are common complications after abdominal surgery. The exact molecular mechanisms that are responsible for these complications remain unclear, and there are no effective methods for preventing adhesion formation or reformation. The aim of the study reported here was to investigate the preventive effects and underlying potential molecular mechanisms of selective cyclooxygenase-2 (COX-2) inhibitors in a rodent model of postoperative intra-abdominal adhesions. Materials and methods The expression of COX-2 in postoperative intra-abdominal adhe-sions and normal peritoneal tissue was examined by immunohistochemistry and Western blot analysis. Assays were performed to elucidate the effect of COX-2 inhibition on hypoxia-induced fibroblast activity in vitro and on intra-abdominal adhesion formation in vivo. Results Hypoxia-induced COX-2 expression in peritoneal fibroblasts was increased in postoperative intra-abdominal adhesions. Inhibition of COX-2 attenuated the activating effect of hypoxia on normal peritoneal fibroblasts in vitro. Data indicate that selective COX-2 inhibitor prevents in vivo intra-abdominal adhesion by inhibition of basic fibroblast growth factor and transforming growth factor-beta expression, but not through an antiangiogenic mechanism. Furthermore, using selective COX-2 inhibitors to prevent intra-abdominal adhesions did not adversely affect the weight, bowel motility, or healing of intestinal anastomoses in a rat model. Conclusion These results show that hypoxia-induced COX-2 expression in peritoneal fibroblasts is involved in the formation of intra-abdominal adhesions. Inhibition of COX-2 prevents postoperative intra-abdominal adhesions through suppression of inflammatory cytokines. PMID:26109851

  2. Human neutrophil peptides upregulate expression of cyclooxygenase-2 and endothelin-1 by inducing oxidative stress

    PubMed Central

    Syeda, Farisa; Tullis, Elizabeth; Slutsky, Arthur S.; Zhang, Haibo

    2016-01-01

    The human neutrophil peptides (HNP) bind to vascular smooth muscle cells and regulate vascular tone. We hypothesized that HNP act on endothelial cells to modulate the expression of vasoactive byproducts. We observed a time- and dose-dependent increase in the expression of cyclooxygenase-2 (COX-2) by human umbilical vein endothelial cells (HUVEC) in response to HNP stimulation, while COX-1 levels remained unchanged. Despite an upregulated expression of COX-2, HNP did not significantly enhance the production of the COX-2-derived prostaglandins PGI2 and PGE2. HNP significantly induced the release of endothelin-1 (ET-1) as well as the formation of nitrotyrosine. The HNP-induced COX-2 and ET-1 production was attenuated by the treatment with the oxygen free radical scavenger N-acetyl-L-cysteine, and the inhibitors of p38 MAPK and NF-κB, respectively. We conclude that HNP may play an important role in the regulation of the course of cardiovascular diseases by activating endothelial cells to produce vasoactive byproducts. PMID:18441204

  3. 5-Lipoxygenase/cyclooxygenase-2 cross-talk through cysteinyl leukotriene receptor 2 in endothelial cells.

    PubMed

    Lötzer, Katharina; Jahn, Steffen; Kramer, Cornelia; Hildner, Markus; Nüsing, Rolf; Funk, Colin D; Habenicht, Andreas J R

    2007-11-01

    The 5-lipoxygenase (5-LO) pathway generates lipid mediators, i.e. the cysteinyl leukotrienes (cysLTs) LTC(4)/LTD(4) and LTB(4). CysLT receptors are expressed in endothelial cells (EC) and EC cysLT(2)-R activation induces diverse pro-inflammatory genes in vitro. We now report that LTD(4) promotes formation of an atherosclerosis-protective and anti-thrombotic eicosanoid by markedly up-regulating EC cyclooxygenase-2 (COX-2). CysLT-induced COX-2 transcripts were transiently up-regulated as determined by microarray and QRT-PCR analyses though COX-2 protein remained elevated for several hours. Prostacyclin formation, measured as its stable metabolite 6-keto-PGF(1alpha), was increased several fold in LTD(4)-stimulated ECs, and was inhibited by the COX-2-specific inhibitor, NS-398. COX-2 up-regulation was Ca(2+)-dependent and was partially blocked by cyclosporin A indicating that the 5-LO/COX-2 cross-talk involved signaling through a nuclear factor of activated T cells (NFAT) dependent pathway. Since prostacyclin is a major blood vessel-protective and anti-thrombotic eicosanoid, the EC cysLT(2)-R may limit its otherwise pro-inflammatory actions through a protective Ca(2+)/calcineurin/NFAT-dependent COX-2 feedback loop. PMID:17991613

  4. Progressive Metaplastic and Dysplastic Changes in Mouse Pancreas Induced by Cyclooxygenase-2 Overexpression1

    PubMed Central

    Colby, Jennifer KL; Klein, Russell D; McArthur, Mark J; Conti, Claudio J; Kiguchi, Kaoru; Kawamoto, Toru; Riggs, Penny K; Pavone, Amy I; Sawicki, Janet; Fischer, Susan M

    2008-01-01

    Cyclooxygenase-2 (COX-2) overexpression is an established factor linking chronic inflammation with metaplastic and neoplastic change in various tissues. We generated transgenic mice (BK5.COX-2) in which elevation of COX-2 and its effectors trigger a metaplasia-dysplasia sequence in exocrine pancreas. Histologic evaluation revealed a chronic pancreatitis-like state characterized by acinar-to-ductal metaplasia and a well-vascularized fibroinflammatory stroma that develops by 3 months. By 6 to 8 months, strongly dysplastic features suggestive of pancreatic ductal adenocarcinoma emerge in the metaplastic ducts. Increased proliferation, cellular atypia, and loss of normal cell/tissue organization are typical features in transgenic pancreata. Alterations in biomarkers associated with human inflammatory and neoplastic pancreatic disease were detected using immunohistochemistry. The abnormal pancreatic phenotype can be completely prevented by maintaining mice on a diet containing celecoxib, a well-characterized COX-2 inhibitor. Despite the high degree of atypia, only limited evidence of invasion to adjacent tissues was observed, with no evidence of distant metastases. However, cell lines derived from spontaneous lesions are aggressively tumorigenic when injected into syngeneic or nude mice. The progressive nature of the metaplastic/dysplastic changes observed in this model make it a valuable tool for examining the transition from chronic inflammation to neoplasia. PMID:18670639

  5. Cyclooxygenase-2 Inhibition Provides Lasting Protection Following Germinal Matrix Hemorrhage in Premature Infant Rats.

    PubMed

    Lekic, Tim; Krafft, Paul R; Klebe, Damon; Rolland, William B; Flores, Jerry; Tang, Jiping; Zhang, John H

    2016-01-01

    Germinal matrix hemorrhage (GMH) is a major cause of brain damage in prematurity and has long-lasting neurological implications. The development of brain inflammation contributes to brain injury, leading to a lifetime of neurologic deficits. PAR-1 and 4 receptors are involved with inflammatory pathways after brain hemorrhage in adult models of stroke, of which cyclooxygenase-2 (COX-2) is a potential mediator. We therefore hypothesized a role for PAR-1, 4/ COX-2 signaling following GMH. Postnatal day 7 Sprague-Dawley rats were subjected to GMH induction, which entailed stereotactic collagenase infusion into the ganglionic eminence. Animals were euthanized at two time points: 72 h (short-term) or 4 weeks (long-term). Short-term COX-2 expression was evaluated in the context of PAR-1 (SCH-79797) and PAR-4 (P4pal10) inhibition. Pups in the long-term group were administered the selective COX-2 inhibitor (NS-398); and the neurobehavioral and pathological examinations were performed 4 weeks later. Pharmacological PAR-1, 4 antagonism normalized COX-2 expression following GMH and reduced hydrocephalus. Early inhibition of COX-2 by NS-398 improved long-term neurobehavioral outcomes. COX-2 signaling plays an important role in brain injury following neonatal GMH, possibly through upstream PAR-1, 4 receptor mechanisms. PMID:26463949

  6. Down-regulation of cyclooxygenase-2 (COX-2) by cannabidiolic acid in human breast cancer cells.

    PubMed

    Takeda, Shuso; Okazaki, Hiroyuki; Ikeda, Eriko; Abe, Satomi; Yoshioka, Yasushi; Watanabe, Kazuhito; Aramaki, Hironori

    2014-01-01

    Metastases are known to be responsible for approximately 90% of breast cancer-related deaths. Cyclooxygenase-2 (COX-2) is involved not only in inflammatory processes, but also in the metastasis of cancer cells; it is expressed in 40% of human invasive breast cancers. To comprehensively analyze the effects of cannabidiolic acid (CBDA), a selective COX-2 inhibitor found in the fiber-type cannabis plant (Takeda et al., 2008), on COX-2 expression and the genes involved in metastasis, we performed a DNA microarray analysis of human breast cancer MDA-MB-231 cells, which are invasive breast cancer cells that express high levels of COX-2, treated with CBDA for 48 hr at 25 µM. The results obtained revealed that COX-2 and Id-1, a positive regulator of breast cancer metastasis, were down-regulated (0.19-fold and 0.52-fold, respectively), while SHARP1 (or BHLHE41), a suppressor of breast cancer metastasis, was up-regulated (1.72-fold) and CHIP (or STUB1) was unaffected (1.03-fold). These changes were confirmed by real-time RT-PCR analyses. Taken together, the results obtained here demonstrated that i) CBDA had dual inhibitory effects on COX-2 through down-regulation and enzyme inhibition, and ii) CBDA may possess the ability to suppress genes that are positively involved in the metastasis of cancer cells in vitro. PMID:25242400

  7. Targeted imaging of cancer by fluorocoxib C, a near-infrared cyclooxygenase-2 probe

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    Cyclooxygenase-2 (COX-2) is a promising target for the imaging of cancer in a range of diagnostic and therapeutic settings. We report a near-infrared COX-2-targeted probe, fluorocoxib C (FC), for visualization of solid tumors by optical imaging. FC exhibits selective and potent COX-2 inhibition in both purified protein and human cancer cell lines. In vivo optical imaging shows selective accumulation of FC in COX-2-overexpressing human tumor xenografts [1483 head and neck squamous cell carcinoma (HNSCC)] implanted in nude mice, while minimal uptake is detectable in COX-2-negative tumor xenografts (HCT116) or 1483 HNSCC xenografts preblocked with the COX-2-selective inhibitor celecoxib. Time course imaging studies conducted from 3 h to 7-day post-FC injection revealed a marked reduction in nonspecific fluorescent signals with retention of fluorescence in 1483 HNSCC tumors. Thus, use of FC in a delayed imaging protocol offers an approach to improve imaging signal-to-noise that should improve cancer detection in multiple preclinical and clinical settings.

  8. Involvement of NADPH oxidases in suppression of cyclooxygenase-2 promoter-dependent transcriptional activities by sesamol

    PubMed Central

    Shimizu, Satomi; Ishigamori, Rikako; Fujii, Gen; Takahashi, Mami; Onuma, Wakana; Terasaki, Masaru; Yano, Tomohiro; Mutoh, Michihiro

    2015-01-01

    Cyclooxygenase-2 (COX-2) has been shown to play an important role in colon carcinogenesis. Moreover, one of the components of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, NADPH oxidase 1 (NOX1), dominantly expressed in the colon, is implicated in the pathogenesis of colon cancer. We have reported that sesamol, one of the lignans in sesame seeds, suppressed COX-2 gene transcriptional activity in human colon cancer cells, and also suppressed intestinal polyp formation in Apc-mutant mice. In the present study, we investigated the involvement of NADPH oxidase in the inhibition of COX-2 transcriptional activity by sesamol. We found that several NADPH oxidase inhibitors, such as apocynin, showed suppressive effects on COX-2 transcriptional activity. Moreover, sesamol significantly suppressed NOX1 mRNA levels in a dose-dependent manner. In addition, we demonstrated that knockdown of NOX1 successfully suppressed COX-2 transcriptional activity. These results suggest that inhibition of NADPH oxidase, especially NOX1, may be involved in the mechanism of the suppression of COX-2 transcriptional activity by sesamol. PMID:25759517

  9. Circadian CLOCK Mediates Activation of Transforming Growth Factor-β Signaling and Renal Fibrosis through Cyclooxygenase 2.

    PubMed

    Chen, Wei-Dar; Yeh, Jih-Kai; Peng, Meng-Ting; Shie, Shian-Sen; Lin, Shuei-Liong; Yang, Chia-Hung; Chen, Tien-Hsing; Hung, Kuo-Chun; Wang, Chun-Chieh; Hsieh, I-Chang; Wen, Ming-Shien; Wang, Chao-Yung

    2015-12-01

    The circadian rhythm regulates blood pressure and maintains fluid and electrolyte homeostasis with central and peripheral clock. However, the role of circadian rhythm in the pathogenesis of tubulointerstitial fibrosis remains unclear. Here, we found that the amplitudes of circadian rhythm oscillation in kidneys significantly increased after unilateral ureteral obstruction. In mice that are deficient in the circadian gene Clock, renal fibrosis and renal parenchymal damage were significantly worse after ureteral obstruction. CLOCK-deficient mice showed increased synthesis of collagen, increased oxidative stress, and greater transforming growth factor-β (TGF-β) expression. TGF-β mRNA expression oscillated with the circadian rhythms under the control of CLOCK-BMAL1 heterodimers. The expression of cyclooxygenase 2 was significantly higher in kidneys from CLOCK-deficient mice with ureteral obstruction. Treatment with a cyclooxygenase 2 inhibitor celecoxib significantly improved renal fibrosis in CLOCK-deficient mice. Taken together, these data establish the importance of the circadian rhythm in tubulointerstitial fibrosis and suggest CLOCK/TGF-β signaling as a novel therapeutic target of cyclooxygenase inhibition. PMID:26458764

  10. Structure of the β-form of human MK2 in complex with the non-selective kinase inhibitor TEI-L03090

    PubMed Central

    Fujino, Aiko; Fukushima, Kei; Kubota, Takaharu; Matsumoto, Yoshiyuki; Takimoto-Kamimura, Midori

    2013-01-01

    Mitogen-activated protein kinase-activated protein kinase 2 (MK2 or MAPKAP-K2), a serine/threonine kinase from the p38 mitogen-activated protein kinase signalling pathway, plays an important role in the production of TNF-α and other cytokines. In a previous report, it was shown that MK2 in complex with the selective inhibitor TEI-I01800 adopts an α-helical glycine-rich loop that is induced by the stable nonplanar conformer of TEI-I01800. To understand the mechanism of the structural change, the structure of MK2 bound to TEI-L03090, which lacks the key substituent found in TEI-I01800, was determined. MK2–TEI-L03090 has a β-sheet glycine-rich loop in common with other kinases, as predicted. This result suggests that a small compound can induce a drastic conformational change in the target protein structure and can be used to design potent and selective inhibitors. PMID:24316826

  11. Inhibition of cyclooxygenase-2 attenuates urinary prostanoid excretion without affecting renal renin expression.

    PubMed

    Kammerl, M C; Nüsing, R M; Seyberth, H W; Riegger, G A; Kurtz, A; Krämer, B K

    2001-09-01

    This study aimed to assess the impact of cyclooxygenase-2 (COX-2) on the secretion and expression of renin in the kidney cortex. For this purpose renocortical COX-2 expression was moderately stimulated by a low-salt diet or strongly stimulated (increase in mRNA about fivefold) by the combination of a low-salt diet and the angiotensin-I-converting enzyme inhibitor ramipril in male Sprague-Dawley rats. None of these manoeuvres changed medullary COX-2 expression or cortical or medullary COX-1 expression. Treatment with low salt plus ramipril but not with low salt alone led to a three- to fourfold increase of the urinary output of all major prostanoids. The selective COX-2 inhibitor rofecoxib (10 mg/kg per day) markedly lowered basal urinary prostanoid excretion and blunted the stimulation of prostanoid excretion during treatment with low salt plus ramipril. The stimulation of renin secretion by the low-salt diet but not by low salt plus ramipril was attenuated by rofecoxib. The low-salt diet led to a moderate increase of renin gene expression, and additional treatment with ramipril caused a 15-fold increase of renin mRNA. However, no effect of rofecoxib on renin gene expression was observed in any group. These findings suggest that stimulation of COX-2 in the renal cortex leads to the increased formation of all major prostanoids. COX-2-derived prostanoids may play a role in the regulation of renin secretion but not in renin gene expression during the intake of a low-salt diet. However, no major relevance of COX-2-derived prostanoids to renin secretion or renin gene expression during ramipril treatment or a combination of ramipril and a low-salt diet was found. PMID:11680616

  12. Signal transducer and activator of transcription 3 (STAT3) inhibitor, S3I-201, acts as a potent and non-selective alkylating agent

    PubMed Central

    Williams, Declan; Resetca, Diana; Wilson, Derek J.; Gunning, Patrick T.

    2016-01-01

    The Signal Transducer and Activator of Transcription 3 (STAT3) oncogene is a master regulator of many human cancers, and a well-recognized target for therapeutic intervention. A well known STAT3 inhibitor, S3I-201 (NSC 74859), is hypothesized to block STAT3 function in cancer cells by binding the STAT3 SH2 domain and disrupt STAT3 protein complexation events. In this study, liquid chromatography tandem mass spectrometry analysis revealed that STAT3, in the presence of S3I-201, showed a minimum of five specific sites of modification, cysteine's 108, 259, 367, 542, and 687. Moreover, a prepared fluorescently labeled chemical probe of S3I-201 (DB-6-055) revealed that S3I-201 non-specifically and globally alkylated intracellular proteins at concentrations consistent with S3I-201's reported IC50. These data are consistent with the hypothesis that S3I-201 is a sub-optimal probe for interrogating STAT3-related cell biology. PMID:26942696

  13. Nitro-arginine methyl ester, a non-selective inhibitor of nitric oxide synthase reduces ibuprofen-induced gastric mucosal injury in the rat.

    PubMed

    Abraham, Premila; K, Indirani; K, Desigamani

    2005-09-01

    Ibuprofen is a commonly used non-steroidal anti-inflammatory drug. Gastrointestinal adverse drug reactions from ibuprofen usage include gastric mucosal ulcers and bleeding. The mechanism by which ibuprofen induces gastric mucosal damage is not clear. The present study is an attempt to examine the role of nitric oxide in the pathogenesis of ibuprofen-induced gastric mucosal damage. Ibuprofen administered orally at the dose of 100 mg/kg body weight for 6 days to the rats resulted in gastric mucosal injury. Serum nitrite and nitrosothiol were increased significantly as compared with the controls, which were treated with the vehicle alone. In the gastric mucosa, lipid peroxidation and protein thiols were increased, and the activity of glyceraldehyde 3-phosphate dehydrogenase, a nitric oxide sensitive enzyme was decreased significantly. Pretreatment of the rats daily with nitric oxide synthase inhibitor, nitro-arginine methyl ester (30 mg/kg body weight) 1 hr before treatment with ibuprofen reduced the gastric mucosal injury. Biochemically, it prevented the rise in serum nitrite levels and the increase in lipid peroxidation and protein thiol levels and the loss of glyceraldehyde 3-phosphate dehydrogenase activity in the gastric mucosa. The results of the present study suggest that increased nitric oxide production may be one of the mechanisms by which ibuprofen produces gastric mucosal injury and that inhibition of nitric oxide synthase reduces gastric mucosal injury. PMID:16133962

  14. Molecular Imaging of Cyclooxygenase-2 in Canine Transitional Cell Carcinomas In Vitro and In Vivo

    PubMed Central

    Cekanova, Maria; Uddin, Md. Jashim; Bartges, Joseph W.; Callens, Amanda; Legendre, Alfred M.; Rathore, Kusum; Wright, Laura; Carter, Amanda; Marnett, Lawrence J.

    2013-01-01

    The enzyme cyclooxygenase-2 (COX-2) is induced at high levels in tumors, but not in surrounding normal tissues, which makes it an attractive target for molecular imaging of cancer. We evaluated the ability of novel optical imaging agent, fluorocoxib A to detect urinary bladder canine transitional cell carcinomas (K9TCC). Here, we show that fluorocoxib A uptake overlapped with COX-2 expression in primary K9TCC cells in vitro. Using subcutaneously implanted primary K9TCC in athymic mice, we demonstrate specific uptake of fluorocoxib A by COX-2-expressing K9TCC xenograft tumors in vivo. Fluorocoxib A uptake by COX-2 expressing xenograft tumors was blocked by 70% (p<0.005) when pre-treated with the COX-2 selective inhibitor, celecoxib (10 mg/kg), 4 h before intravenous administration of fluorocoxib A (1 mg/kg). Fluorocoxib A was taken up by COX-2-expressing tumors, but not by COX-2 negative human UMUC-3 xenograft tumors. UMUC-3 xenograft tumors with no expression of COX-2 showed no uptake of fluorocoxib A. In addition, fluorocoxib A uptake was evaluated in 5 dogs diagnosed with TCC. Fluorocoxib A specifically detected COX-2-expressing K9TCC during cystoscopy in vivo, but was not detected in normal urothelium. Taken together, our findings show that fluorocoxib A selectively bound to COX-2 expressing primary K9TCC cells in vitro, COX-2 expressing K9TCC xenografts tumors in nude mice and heterogeneous canine TCC during cystoscopy in vivo. Spontaneous cancers in companion animals offer a unique translational model for evaluation of novel imaging and therapeutic agents using primary cancer cells in vitro and in heterogeneous cancers in vivo. PMID:23531445

  15. Cyclooxygenase 2 pathway and its therapeutic inhibition in superantigen-induced toxic shock.

    PubMed

    Rajagopalan, Govindarajan; Asmann, Yan W; Lytle, Anna K; Tilahun, Ashenafi Y; Theuer, Jayne E; Smart, Michele K; Patel, Robin; David, Chella S

    2008-12-01

    Bacterial superantigens are a family of exotoxins that are the most potent T-cell activators known. Because of their ability to induce strong immune activation, superantigens have been implicated in a variety of diseases ranging from self-limiting food poisoning to more severe toxic shock syndrome (TSS) and have the potential to be used as agents of bioterrorism. Nonetheless, the precise molecular mechanisms by which T-cell activation by superantigens lead to acute systemic inflammatory response, multiple organ dysfunction, and ultimately death are unclear. Inadequate understanding of the pathogenesis has resulted in lack of development of effective therapy for superantigen-induced TSS. To fill these deficiencies, we systematically dissected the molecular pathogenesis of superantigen-induced TSS using the humanized human leukocyte antigen-DR3 transgenic mouse model by microarray-based gene expression profiling. Splenic expression of prostaglandin-endoperoxide synthase 2 (PTGS-2; also called cyclooxygenase 2 or COX-2) gene was increased by several hundred folds shortly after systemic superantigen (staphylococcal enterotoxin B [SEB]) exposure. In addition, expressions of several genes associated with eicosanoid pathway were significantly modulated by SEB, as analyzed by dedicated software. Given the importance of the COX-2 pathway in inflammation, we examined whether therapeutic inhibition of COX-2 by a highly selective inhibitor, CAY10404, could be beneficial. Our studies showed that i.p. administration of CAY10404 (50 mg/kg) immediately after challenge with 10 microg of SEB was unable to inhibit SEB-induced in vivo cytokine/chemokine production or T-cell activation/proliferation and did not prevent superantigen-associated thymocyte apoptosis. PMID:18496243

  16. Potential Pathogenetic Implications of Cyclooxygenase-2 Overexpression in B Chronic Lymphoid Leukemia Cells

    PubMed Central

    Secchiero, Paola; Barbarotto, Elisa; Gonelli, Arianna; Tiribelli, Mario; Zerbinati, Carlotta; Celeghini, Claudio; Agostinelli, Claudio; Pileri, Stefano A.; Zauli, Giorgio

    2005-01-01

    Evidence suggests that cyclooxygenase-2 (COX-2) increases tumorigenic potential by promoting resistance to apoptosis. Because B chronic lymphoid leukemia (B-CLL) cells exhibit a defective apoptotic response, we analyzed CD19+ B lymphocytes purified from the peripheral blood of B-CLL patients. Microarray analysis showed a variable (up to 38-fold) increase in the steady-state mRNA levels of COX-2 in B-CLL lymphocytes compared with normal CD19+ B lymphocytes. The up-regulation of COX-2 in B-CLL cells was confirmed by reverse transcriptase-polymerase chain reaction and Western blot analyses. Moreover, immunohistochemical analysis of B-CLL bone marrow infiltrates confirmed clear expression of COX-2 in leukemic cells. Ex vivo treatment with the COX-2 inhibitor NS-398 significantly decreased the survival of leukemic cells by increasing the rate of spontaneous apoptosis in 13 of 16 B-CLL samples examined, but it did not affect the survival of normal lymphocytes. Pretreatment with NS-398 significantly potentiated the cytotoxicity induced by chlorambucil in 8 of 16 B-CLL samples examined. Moreover, although recombinant tumor necrosis factor-related apoptosis inducing ligand (TRAIL)/Apo2L showed little cytotoxic effect in most B-CLL samples examined, pretreatment with NS-398 sensitized 8 of 16 B-CLL samples to TRAIL-induced apoptosis. Taken together, our data indicate that COX-2 overexpression likely represents an additional mechanism of resistance to apoptosis in B-CLL and that pharmacological suppression of COX-2 might enhance chemotherapy-mediated apoptosis. PMID:16314473

  17. Cyclooxygenase-2 inhibition provides lasting protection against neonatal hypoxic-ischemic brain injury

    PubMed Central

    Fathali, Nancy; Ostrowski, Robert P.; Lekic, Tim; Jadhav, Vikram; Tong, Wenni; Tang, Jiping; Zhang, John H.

    2009-01-01

    Objective The development of brain inflammation largely contributes to neonatal brain injury that may lead to a lifetime of neurologic deficits. The present study was designed to investigate whether inhibition of cyclooxygenase-2 (COX-2), a critical component of the inflammatory pathway, is neuroprotective in a neonatal rat model of cerebral hypoxia-ischemia (HI). Design Laboratory investigation. Setting University research laboratory. Subjects Postnatal day-10 Sprague-Dawley rats. Interventions Neonatal HI was induced by ligation of the right common carotid artery followed by two hours of hypoxia (8% O2). The pups in treatment groups were administered 10mg/kg (low dose) or 30mg/kg (high dose) of a known selective COX-2 inhibitor (NS398). Animals were euthanized at three time points: 72hrs, 2wks, or 6wks. Inflammation outcomes were assessed at 72hrs; brain damage was assessed at 2- and 6wks along with other organs (heart, spleen). Detailed neurobehavioral examination was performed at 6wks. Measurements and Main Results Pharmacological inhibition of COX-2 markedly increased survivability within the first 72hrs compared to untreated rats (100% vs. 72%). Low- and high-dose NS398 significantly attenuated the loss of brain and body weights observed after HI. Neurobehavioral outcomes were significantly improved in some parameters with low dose treatment; while, high dose treatment consistently improved all neurological deficits. Immunohistochemical results showed a marked decrease in macrophage, microglial, and neutrophil abundance in ipsilateral brain of NS398 treated group along with a reduction in interleukin-6 expression. Conclusions Selective COX-2 inhibition protected neonatal rats against death, progression of brain injury, growth retardation, and neurobehavioral deficits after a hypoxic-ischemic insult. PMID:20029340

  18. Inhibition of cyclooxygenase-2 in hematopoietic cells results in salt-sensitive hypertension

    PubMed Central

    Zhang, Ming-Zhi; Yao, Bing; Wang, Yinqiu; Yang, Shilin; Wang, Suwan; Fan, Xiaofeng; Harris, Raymond C.

    2015-01-01

    Inhibition of prostaglandin (PG) production with either nonselective or selective inhibitors of cyclooxygenase-2 (COX-2) activity can induce or exacerbate salt-sensitive hypertension. This effect has been previously attributed to inhibition of intrinsic renal COX-2 activity and subsequent increase in sodium retention by the kidney. Here, we found that macrophages isolated from kidneys of high-salt–treated WT mice have increased levels of COX-2 and microsomal PGE synthase–1 (mPGES-1). Furthermore, BM transplantation (BMT) from either COX-2–deficient or mPGES-1–deficient mice into WT mice or macrophage-specific deletion of the PGE2 type 4 (EP4) receptor induced salt-sensitive hypertension and increased phosphorylation of the renal sodium chloride cotransporter (NCC). Kidneys from high-salt–treated WT mice transplanted with Cox2–/– BM had increased macrophage and T cell infiltration and increased M1- and Th1-associated markers and cytokines. Skin macrophages from high-salt–treated mice with either genetic or pharmacologic inhibition of the COX-2 pathway expressed decreased M2 markers and VEGF-C production and exhibited aberrant lymphangiogenesis. Together, these studies demonstrate that COX-2–derived PGE2 in hematopoietic cells plays an important role in both kidney and skin in maintaining homeostasis in response to chronically increased dietary salt. Moreover, these results indicate that inhibiting COX-2 expression or activity in hematopoietic cells can result in a predisposition to salt-sensitive hypertension. PMID:26485285

  19. Role of cyclooxygenase-2 in the prolonged regulation of renal function.

    PubMed

    Roig, Francisco; Llinás, Maria T; López, Ruth; Salazar, F Javier

    2002-11-01

    The role of cyclooxygenase-2 (COX-2) in the prolonged regulation of renal function was evaluated during changes in sodium intake and reduction of NO synthesis. It was evaluated in conscious dogs by administering a selective inhibitor (nimesulide) during 8 consecutive days. Nimesulide administration to dogs with normal or high sodium load did not modify glomerular filtration rate but reduced renal blood flow (16%; P<0.05). The vasoconstriction elicited by COX-2 inhibition was greater when NO production was inhibited because glomerular filtration rate decreased by >25% when nimesulide was administered to dogs with a reduced NO synthesis. During low sodium intake, COX-2 inhibition elicited a decrease (P<0.05) of both glomerular filtration rate (34%) and renal blood flow (31%). Sodium excretion only decreased (P<0.05) during the first day of COX-2 inhibition in dogs with normal or high sodium load. The increase in plasma potassium levels elicited by COX-2 inhibition was greater in dogs with low sodium intake and was enhanced when NO production was inhibited. This change in potassium was not secondary to a decrease in plasma aldosterone levels. The results of this study suggest that COX-2-derived metabolites (1) play a more important role in the long-term regulation of renal hemodynamic when sodium intake is low, (2) protect the renal vasculature from the vasoconstriction secondary to a reduction in NO, (3) are only acutely involved in regulating urinary sodium excretion, and (4) play a more important role in regulating plasma potassium concentration when NO synthesis is reduced. PMID:12411468

  20. Pre-existent asymmetry in the human cyclooxygenase-2 sequence homodimer.

    PubMed

    Dong, Liang; Sharma, Narayan P; Jurban, Brice J; Smith, William L

    2013-10-01

    Prostaglandin endoperoxide H synthase-2 (PGHS-2), also known as cyclooxygenase-2 (COX-2), is a sequence homodimer. However, the enzyme exhibits half-site heme and inhibitor binding and functions as a conformational heterodimer having a catalytic subunit (Ecat) with heme bound and an allosteric subunit (Eallo) lacking heme. Some recombinant heterodimers composed of a COX-deficient mutant subunit and a native subunit (i.e. Mutant/Native PGHS-2) have COX activities similar to native PGHS-2. This suggests that the presence of heme plus substrate leads to the subunits becoming lodged in a semi-stable Eallo-mutant/Ecat-Native∼heme form during catalysis. We examined this concept using human PGHS-2 dimers composed of combinations of Y385F, R120Q, R120A, and S530A mutant or native subunits. With some heterodimers (e.g. Y385F/Native PGHS-2), heme binds with significantly higher affinity to the native subunit. This correlates with near native COX activity for the heterodimer. With other heterodimers (e.g. S530A/Native PGHS-2), heme binds with similar affinities to both subunits, and the COX activity approximates that expected for an enzyme in which each monomer contributes equally to the net COX activity. With or without heme, aspirin acetylates one-half of the subunits of the native PGHS-2 dimer, the Ecat subunits. Subunits having an S530A mutation are refractory to acetylation. Curiously, aspirin acetylates only one-quarter of the monomers of S530A/Native PGHS-2 with or without heme. This implies that there are comparable amounts of two noninterchangeable species of apoenzymes, Eallo-S530A/Ecat-Native and Eallo-Native/Ecat-S530A. These results suggest that native PGHS-2 assumes a reasonably stable, asymmetric Eallo/Ecat form during its folding and processing. PMID:23955344

  1. Cyclo-oxygenase-2 inhibition and endothelium-dependent vasodilation in younger vs. older healthy adults

    PubMed Central

    Eisenach, John H; Gullixson, Leah R; Allen, Alexander R; Kost, Susan L; Nicholson, Wayne T

    2014-01-01

    Aim A major feature of endothelial dysfunction is reduced endothelium-dependent vasodilation, which in ageing may be due to decreased production of endothelial prostacyclin, or nitric oxide (NO), or both. Method We tested this hypothesis in 12 younger (age 18–38 years, six women) and 12 older healthy adults (age 55–73 years, six post-menopausal women). Endothelium-dependent vasodilation was assessed by the forearm vascular conductance (FVC) response to intra-arterial acetylcholine (ACh) (0.5, 1.0, 2.0, 4.0 μg dl−1 forearm tissue min−1) before and 90 min after inhibition of the enzyme cyclo-oxygenase-2 (COX-2) with oral celecoxib (400 mg), followed by the addition of endothelial NO synthase inhibition with intra-arterial NG-monomethyl-l arginine acetate (L-NMMA). Results Ageing was associated with a significantly reduced FVC response to ACh (P = 0.009, age-by-dose interaction; highest dose FVC ± SEM in ageing: 11.2 ± 1.4 vs. younger: 17.7 ± 2.4 units, P = 0.02). Celecoxib did not reduce resting FVC or the responses to ACh in any group. L-NMMA significantly reduced resting FVC and the responses to ACh in all groups, and absolute FVC values following L-NMMA were similar between groups. Conclusion In healthy normotensive younger and older adults, there is minimal contribution of prostacyclin to ACh-mediated vasodilation, yet the NO component of vasodilation is reduced with ageing. In the clinical context, these findings suggest that acute administration of medications that inhibit prostacyclin (i.e. COX-2 inhibitors) evoke modest vascular consequences in healthy persons. Additional studies are necessary to test whether chronic use of COX-2 medications reduces endothelium dependent vasodilation in older persons with or without cardiovascular risk factors. PMID:24698105

  2. Pre-existent Asymmetry in the Human Cyclooxygenase-2 Sequence Homodimer*

    PubMed Central

    Dong, Liang; Sharma, Narayan P.; Jurban, Brice J.; Smith, William L.

    2013-01-01

    Prostaglandin endoperoxide H synthase-2 (PGHS-2), also known as cyclooxygenase-2 (COX-2), is a sequence homodimer. However, the enzyme exhibits half-site heme and inhibitor binding and functions as a conformational heterodimer having a catalytic subunit (Ecat) with heme bound and an allosteric subunit (Eallo) lacking heme. Some recombinant heterodimers composed of a COX-deficient mutant subunit and a native subunit (i.e. Mutant/Native PGHS-2) have COX activities similar to native PGHS-2. This suggests that the presence of heme plus substrate leads to the subunits becoming lodged in a semi-stable Eallo-mutant/Ecat-Native∼heme form during catalysis. We examined this concept using human PGHS-2 dimers composed of combinations of Y385F, R120Q, R120A, and S530A mutant or native subunits. With some heterodimers (e.g. Y385F/Native PGHS-2), heme binds with significantly higher affinity to the native subunit. This correlates with near native COX activity for the heterodimer. With other heterodimers (e.g. S530A/Native PGHS-2), heme binds with similar affinities to both subunits, and the COX activity approximates that expected for an enzyme in which each monomer contributes equally to the net COX activity. With or without heme, aspirin acetylates one-half of the subunits of the native PGHS-2 dimer, the Ecat subunits. Subunits having an S530A mutation are refractory to acetylation. Curiously, aspirin acetylates only one-quarter of the monomers of S530A/Native PGHS-2 with or without heme. This implies that there are comparable amounts of two noninterchangeable species of apoenzymes, Eallo-S530A/Ecat-Native and Eallo-Native/Ecat-S530A. These results suggest that native PGHS-2 assumes a reasonably stable, asymmetric Eallo/Ecat form during its folding and processing. PMID:23955344

  3. Cyclooxygenase-2 Inhibitory and Antioxidant Compounds from the Truffle Elaphomyces granulatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Flaxseed oil increases aortic reactivity to phenylephrine through reactive oxygen species and the cyclooxygenase-2 pathway in rats

    PubMed Central

    2014-01-01

    Background Flaxseed oil has the highest concentration of omega-3 α-linolenic acid, which has been associated with cardiovascular benefit. However, the mechanism underlying the vascular effects induced through flaxseed oil is not well known. Thus, in the present study, we investigated the effects of flaxseed oil on vascular function in isolated rat aortic rings. Methods Wistar rats were treated daily with flaxseed oil or a control (mineral oil) intramuscular (i.m.) for fifteen days. Isolated aortic segments were used to evaluate cyclooxygenase-2 (COX-2) protein expression, superoxide anion levels and vascular reactivity experiments. Results Flaxseed oil treatment increased the vasoconstrictor response of aortic rings to phenylephrine. Endothelium removal increased the response to phenylephrine in aortic segments isolated from both groups, but the effect was smaller in the treated group. L-NAME incubation similarly increased the phenylephrine response in segments from both groups. The TXA2 synthase inhibitor furegrelate, the selective COX-2 inhibitor NS 398, the TP receptor antagonist SQ 29.548, the reactive oxygen species (ROS) scavenger apocynin, the superoxide anion scavengers tiron and the phospholipase A2 inhibitor dexamethasone partially reversed the flaxseed oil-induced increase in reactivity to phenylephrine. Conclusions These findings suggest that flaxseed oil treatment increased vascular reactivity to phenylephrine through an increase in ROS production and COX-2-derived TXA2 production. The results obtained in the present study provide new insight into the effects of flaxseed oil treatment (i.m.) on vascular function. PMID:24993607

  5. The structure of ibuprofen bound to cyclooxygenase-2.

    PubMed

    Orlando, Benjamin J; Lucido, Michael J; Malkowski, Michael G

    2015-01-01

    The cyclooxygenases (COX-1 and COX-2) catalyze the rate-limiting step in the biosynthesis of prostaglandins, and are the pharmacological targets of non-steroidal anti-inflammatory drugs (NSAIDs) and COX-2 selective inhibitors (coxibs). Ibuprofen (IBP) is one of the most commonly available over-the-counter pharmaceuticals in the world. The anti-inflammatory and analgesic properties of IBP are thought to arise from inhibition of COX-2 rather than COX-1. While an X-ray crystal structure of IBP bound to COX-1 has been solved, no such structure exists for the cognate isoform COX-2. We have determined the crystal structure of muCOX-2 with a racemic mixture of (R/S)-IBP. Our structure reveals that only the S-isomer of IBP was bound, indicating that the S-isomer possesses higher affinity for COX-2 than the R-isomer. Mutational analysis of Arg-120 and Tyr-355 at the entrance of the cyclooxygenase channel confirmed their role in binding and inhibition of COX-2 by IBP. Our results provide the first atomic level detail of the interaction between IBP and COX-2. PMID:25463020

  6. THE STRUCTURE OF IBUPROFEN BOUND TO CYCLOOXYGENASE-2

    PubMed Central

    Orlando, Benjamin J.; Lucido, Michael J.; Malkowski, Michael G.

    2014-01-01

    The cyclooxygenases (COX-1 and COX-2) catalyze the rate-limiting step in the biosynthesis of prostaglandins, and are the pharmacological targets of non-steroidal anti-inflammatory drugs (NSAIDs) and COX-2 selective inhibitors (coxibs). Ibuprofen (IBP) is one of the most commonly available over-the-counter pharmaceuticals in the world. The anti-inflammatory and analgesic properties of IBP are thought to arise from inhibition of COX-2 rather than COX-1. While an x-ray crystal structure of IBP bound to COX-1 has been solved, no such structure exists for the cognate isoform COX-2. We have determined the crystal structure of muCOX-2 with a racemic mixture of (R/S)-IBP. Our structure reveals that only the S-isomer of IBP was bound, indicating that the S-isomer possesses higher affinity for COX-2 than the R-isomer. Mutational analysis of Arg-120 and Tyr-355 at the entrance of the cyclooxygenase channel confirmed their role in binding and inhibition of COX-2 by IBP. Our results provide the first atomic level detail of the interaction between IBP and COX-2. PMID:25463020

  7. Isomeric iodinated analogs of nimesulide: Synthesis, physicochemical characterization, cyclooxygenase-2 inhibitory activity, and transport across Caco-2 cells.

    PubMed

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

    2016-08-15

    Isomeric iodinated derivatives of nimesulide, with an iodine substituent on the phenoxy ring, were prepared with the aim of identifying potential candidate compounds for the development of imaging agents targeting cyclooxygenase-2 (COX-2) in the brain. Both the experimental logP7.4 and pKa values for these iodinated analogs were in the acceptable range for passive brain penetration. The para-iodo-substituted analog was a more potent and selective COX-2 inhibitor than nimesulide, with a potency that was comparable to the reference drug, celecoxib. Iodination at the ortho- or meta-position of the phenoxy ring was associated with a substantial loss of COX-2 inhibitory activity. Transport studies across Caco-2 cell monolayers in the presence and absence of a P-glycoprotein (P-gp) inhibitor, verapamil, indicated that the para-iodo-substituted analog was not a P-gp transport substrate; this feature is a prerequisite for potential in vivo brain imaging compounds. The para-iodo-substituted analog of nimesulide appears to be an attractive candidate for the development of radioiodine-labeled tracers for in vivo brain imaging of COX-2 levels. PMID:27325447

  8. Sesamol suppresses cyclooxygenase-2 transcriptional activity in colon cancer cells and modifies intestinal polyp development in ApcMin/+ mice

    PubMed Central

    Shimizu, Satomi; Fujii, Gen; Takahashi, Mami; Nakanishi, Ruri; Komiya, Masami; Shimura, Misato; Noma, Nobuharu; Onuma, Wakana; Terasaki, Masaru; Yano, Tomohiro; Mutoh, Michihiro

    2014-01-01

    Excessive prostaglandin production by cyclooxygenase-2 in stromal and epithelial cells is a causative factor of colorectal carcinogenesis. Thus, compounds which inhibit cyclooxygenase-2 transcriptional activity in colon epithelial cells could be candidates for anti-carcinogenic agents. A cyclooxygenase-2 transcriptional activity in the human colon cancer cell line DLD-1 has been measured using a β-galactosidase reporter gene system. Using this system, we demonstrated that the decrease in basal cyclooxygenase-2 transcriptional activities at 100 µM sesamol, one of the lignans in sesame seeds, was 50%. Other compounds in sesame seeds such as sesamin, sesamolin, ferulic acid, and syringic acid did not exhibit significant suppression of cyclooxygenase-2 transcriptional activity at up to 100 µM. In a following experiment, 6-week-old male Min mice, Apc-deficient mice, were divided into a non-treated and 500 ppm sesamol groups. At the age of 15 weeks, it was found that treatment with sesamol decreased the number of polyps in the middle part of small intestine to 66.1% of the untreated value. Moreover, sesamol suppressed cyclooxygenase-2 and cytosolic prostaglandin E2 synthase mRNA in the polyp parts. The present findings may demonstrate the novel anti-carcinogenetic property of sesamol, and imply that agents that can suppress cyclooxygenase-2 expression may be useful cancer chemopreventive agents. PMID:24688218

  9. Acceleration of cardiovascular disease by a dysfunctional prostacyclin receptor mutation: potential implications for cyclooxygenase-2 inhibition.

    PubMed

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

    2008-04-25

    Recent increased adverse cardiovascular events observed with selective cyclooxygenase-2 inhibition led to the withdrawal of rofecoxib (Vioxx) and valdecoxib (Bextra), but the mechanisms underlying these atherothrombotic events remain unclear. Prostacyclin is the major end product of cyclooxygenase-2 in vascular endothelium. Using a naturally occurring mutation in the prostacyclin receptor, we report for the first time that a deficiency in prostacyclin signaling through its G protein-coupled receptor contributes to atherothrombosis in human patients. We report that a prostacyclin receptor variant (R212C) is defective in adenylyl cyclase activation in both patient blood and in an in vitro COS-1 overexpression system. This promotes increased platelet aggregation, a hallmark of atherothrombosis. Our analysis of patients in 3 separate white cohorts reveals that this dysfunctional receptor is not likely an initiating factor in cardiovascular disease but that it accelerates the course of disease in those patients with the greatest risk factors. R212C was associated with cardiovascular disease only in the high cardiovascular risk cohort (n=980), with no association in the low-risk cohort (n=2293). In those at highest cardiovascular risk, both disease severity and adverse cardiovascular events were significantly increased with R212C when compared with age- and risk factor-matched normal allele patients. We conclude that for haploinsufficient mutants, such as the R212C, the enhanced atherothrombotic phenotype is likely dependent on the presence of existing atherosclerosis or injury (high risk factors), analogous to what has been observed in the cyclooxygenase-2 inhibition studies or prostacyclin receptor knockout mice studies. Combining both biochemical and clinical approaches, we conclude that diminished prostacyclin receptor signaling may contribute, in part, to the underlying adverse cardiovascular outcomes observed with cyclooxygenase-2 inhibition. PMID:18323528

  10. The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2

    PubMed Central

    Maioli, N.A.; Zarpelon, A.C.; Mizokami, S.S.; Calixto-Campos, C.; Guazelli, C.F.S.; Hohmann, M.S.N.; Pinho-Ribeiro, F.A.; Carvalho, T.T.; Manchope, M.F.; Ferraz, C.R.; Casagrande, R.; Verri, W.A.

    2015-01-01

    It is currently accepted that superoxide anion (O2 •−) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment. PMID:25714890

  11. The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2.

    PubMed

    Maioli, N A; Zarpelon, A C; Mizokami, S S; Calixto-Campos, C; Guazelli, C F S; Hohmann, M S N; Pinho-Ribeiro, F A; Carvalho, T T; Manchope, M F; Ferraz, C R; Casagrande, R; Verri, W A

    2015-04-01

    It is currently accepted that superoxide anion (O2•-) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment. PMID:25714890

  12. Role of cyclooxygenase-2 in the development of interstitial fibrosis in kidneys following unilateral ureteral obstruction in mice.

    PubMed

    Kamata, Mariko; Hosono, Kanako; Fujita, Tomoe; Kamata, Kouju; Majima, Masataka

    2015-03-01

    Unilateral ureteral obstruction (UUO) induced tubulointerstitial fibrosis in kidneys mimics the pathogenesis of chronic kidney diseases and is considered a suitable model for studying the mechanisms leading to fibrosis. To study the role of cyclooxygenase-2 (COX-2) in kidney fibrosis, we investigated whether a selective COX-2 inhibitor, celecoxib, affected renal interstitial fibrosis during UUO in mice. To induce UUO, the left proximal ureter was ligated in male C57BL/6 mice. The mice were fed a diet with or without celecoxib from the day of UUO induction. Following UUO, the renal pelvis was observed to be dilated and the kidney cortex was significantly thinner than that of sham-operated mice. Immunofluorescent staining of type I, III, and IV collagen in UUO kidneys revealed that interstitial collagen deposition was significantly increased in the celecoxib-treated group. Expression of type I, III, and IV collagen in UUO kidneys was also significantly higher in the celecoxib-treated group than in the vehicle-treated group. In the celecoxib-treated group, mRNA levels of TGF-β/FGF-2 were also significantly higher than those in the vehicle-treated group. The present study demonstrates that COX-2 plays a protective role against fibrosis in UUO kidneys and suggests that supplementation of COX-2 products, such as PG analogues, will be a good option for preventing interstitial fibrosis. PMID:25776498

  13. Inhibition of Nuclear Factor κB Activation and Cyclooxygenase-2 Expression by Aqueous Extracts of Hispanic Medicinal Herbs

    PubMed Central

    Gonzales, Amanda M.; Hunsaker, Lucy A.; Franco, Carolina R.; Royer, Robert E.; Vander Jagt, David L.; Vander Jagt, Dorothy J.

    2010-01-01

    Abstract Nonsteroidal anti-inflammatory drugs (NSAIDs) are a primary choice of therapy for diseases with a chronic inflammatory component. Unfortunately, long-term NSAID therapy is often accompanied by severe side effects, including cardiovascular and gastrointestinal complications. Because of this, there is critical need for identification of new and safer treatments for chronic inflammation to circumvent these side effects. Inflammatory diseases have been successfully remedied with natural herbs by many cultures. To better understand the potential of natural herbs in treating chronic inflammation and to identify their mechanism of action, we have evaluated the anti-inflammatory activities of 20 medicinal herbs commonly used in the Hispanic culture. We have established a standardized method for preparing aqueous extracts (teas) from the selected medicinal herbs and screened for inhibition of tumor necrosis factor-α-induced activation of nuclear factor κB (NF-κB), which is the central signaling pathway of the inflammatory response. A number of herbal teas were identified that exhibited significant anti-inflammatory activity. In particular, tea from the herb commonly called laurel was found to be an especially potent inhibitor of NF-κB-dependent cyclooxygenase-2 gene expression and prostaglandin E2 production in cultured murine macrophages. These findings indicate that laurel tea extract contains potent anti-inflammatory compounds that function by inhibiting the major signal transduction pathway responsible for inducing an inflammatory event. Based on these results, laurel may represent a new, safe therapeutic agent for managing chronic inflammation. PMID:20482259

  14. Interaction between cyclooxygenase-2 and insulin-like growth factor in breast cancer: A new field for prevention and treatment

    PubMed Central

    TAROMARU, GIULIANA CÁSSIA MORRONE; DE OLIVEIRA, VILMAR MARQUES; SILVA, MARIA ANTONIETA LONGO GALVÃO; MONTOR, WAGNER RICARDO; BAGNOLI, FABIO; RINALDI, JOSÉ FRANCISCO; AOKI, TSUTOMU

    2011-01-01

    The objective of this study was to evaluate the correlation between cyclooxygenase-2 (COX-2) and markers of cell proliferation and apoptosis, including, Bcl-2, Bax, Ki-67 and the type I insulin-like growth factor (IGF) receptor (IGF1-R) in ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDC), present in the same surgical specimen. A total of 110 cases were evaluated using tissue microarrays. Cases were classified in scores from 0 to 3 according to pre-defined methods. The results showed that the positivity rates were COX-2 in 87% of cases in DCIS and IDC; Bcl-2 in 55% of cases in DCIS and IDC; Bax in 23% of cases in IDC and 19% in DCIS, IGF-1 in 24% of cases in DCIS and IDC; and Ki-67 in 81% of cases in DCIS and IDC. We also observed a positive correlation between the expression of COX-2 and IGF1-R (p=0.045). Our results demonstrate a positive correlation between the expression of COX-2 and IGF1-R in DCIS and IDC, demonstrating that they are involved in breast cancer carcinogenesis. Further studies are required to prove the effectiveness of COX-2 and IGF1-R inhibitors for the prevention and treatment of breast cancer, as well as to explain their mechanism of action. PMID:22740976

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

    SciTech Connect

    Aguado, Andrea; Galán, María; Zhenyukh, Olha; Wiggers, Giulia A.; Roque, Fernanda R.; Redondo, Santiago; Peçanha, Franck; Martín, Angela; Fortuño, Ana; Cachofeiro, Victoria; Tejerina, Teresa; Salaices, Mercedes; and others

    2013-04-15

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

  16. Activated human B lymphocytes express cyclooxygenase-2 and cyclooxygenase inhibitors attenuate antibody production.

    PubMed

    Ryan, Elizabeth P; Pollock, Stephen J; Pollack, Stephen J; Murant, Thomas I; Bernstein, Steven H; Felgar, Raymond E; Phipps, Richard P

    2005-03-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for the treatment of inflammatory diseases and target cyclooxygenases 1 and 2 (Cox-1, Cox-2) that are responsible for PG production. Newer Cox-2-selective drugs have been heavily prescribed to quench inflammation. Little is known about whether or not these drugs influence human B lymphocytes and their ability to produce Ab. We report herein that activated human B cells not only highly express Cox-2 and produce PGs, but that the NSAID indomethacin and Cox-2-selective drugs profoundly inhibit the ability of human B cells to produce IgG and IgM in vitro. Human blood B cells highly express Cox-2 mRNA and protein and produce PGs after activation with CD40L, pansorbin, or CD40L plus BCR engagement. Cox-2 is also highly expressed by human tonsil B cells, as shown by immunohistochemistry. Cox-inhibiting drugs modestly affect purified B cell proliferation but profoundly reduce Ab production. The ability of whole blood to produce IgM and IgG following stimulation is also strongly inhibited. In support that Cox-2 plays a seminal role in B lymphocyte Ab production, Cox-2 knockout mice have 64% less IgM and 35% less IgG than normal littermate controls. These findings support that NSAIDs and the new Cox-2-selective drugs have an unsuspected target, the B cell, and attenuate Ab production in humans. Use of NSAIDs may therefore influence autoantibody production in autoimmune diseases and may dampen humoral immunity in response to antigenic challenge/vaccination. PMID:15728468

  17. Propyphenazone-based analogues as prodrugs and selective cyclooxygenase-2 inhibitors.

    PubMed

    Radwan, Mohamed F; Dalby, Kevin N; Kaoud, Tamer S

    2014-09-11

    Improving the gastrointestinal safety profile of nonsteroidal anti-inflammatory drugs (NSAIDs) is an important goal. Herein, we report two strategies, using the nonacidic propyphenazone structure, with potential to overcome the side effects of NSAIDs. Propyphenazone was employed to temporarily mask the free acid group of the widely used NSAIDs ibuprofen, diclofenac, and ketoprofen to develop three mutual prodrugs hypothesized to have minimal GI irritation. The three prodrugs exhibit in vivo anti-inflammatory and analgesic activities with improved potency over each parent drug when compared to a nonhydrolyzable control betahistine-propyphenazone (BET-MP). Additionally, ANT-MP formed by the irreversible coupling of propyphenazone and 4-aminoantipyrine, displayed exceptional COXII selectivity (COXII IC50 of 0.97 ± 0.04 μM, compared to no observed inhibition of COXI at 160 μM). Inhibition of COXII suppresses inflammatory diseases without affecting COXI-mediated GI tract events. ANT-MP exhibited maximal analgesic effect when tested in vivo in an abdominal writhing assay (100% protection) and its anti-inflammatory activity showed a peak at 2 h in a carrageenan-induced paw edema model. Its unique selectivity toward the COXII enzyme was investigated using molecular modeling techniques. PMID:25221653

  18. Propyphenazone-Based Analogues as Prodrugs and Selective Cyclooxygenase-2 Inhibitors

    PubMed Central

    2014-01-01

    Improving the gastrointestinal safety profile of nonsteroidal anti-inflammatory drugs (NSAIDs) is an important goal. Herein, we report two strategies, using the nonacidic propyphenazone structure, with potential to overcome the side effects of NSAIDs. Propyphenazone was employed to temporarily mask the free acid group of the widely used NSAIDs ibuprofen, diclofenac, and ketoprofen to develop three mutual prodrugs hypothesized to have minimal GI irritation. The three prodrugs exhibit in vivo anti-inflammatory and analgesic activities with improved potency over each parent drug when compared to a nonhydrolyzable control betahistine–propyphenazone (BET–MP). Additionally, ANT–MP formed by the irreversible coupling of propyphenazone and 4-aminoantipyrine, displayed exceptional COXII selectivity (COXII IC50 of 0.97 ± 0.04 μM, compared to no observed inhibition of COXI at 160 μM). Inhibition of COXII suppresses inflammatory diseases without affecting COXI-mediated GI tract events. ANT–MP exhibited maximal analgesic effect when tested in vivo in an abdominal writhing assay (100% protection) and its anti-inflammatory activity showed a peak at 2 h in a carrageenan-induced paw edema model. Its unique selectivity toward the COXII enzyme was investigated using molecular modeling techniques. PMID:25221653

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

    PubMed Central

    Cintra, Francisco Fontes; Etchebehere, Mauricio; Gonçalves, José Carlos Barbi; Cassone, Alejandro Enzo; Amstalden, Eliane Maria Ingrid

    2011-01-01

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

  20. Cyclooxygenase-2 Expression in Non-Small Cell Lung Cancer Correlates With Hypertrophic Osteoarthropathy.

    PubMed

    Rotas, Ioannis; Cito, Giovanni; Letovanec, Igor; Christodoulou, Michel; Perentes, Jean Y

    2016-02-01

    Hypertrophic osteoarthrpathy (HO) is a rare paraneoplasic syndrome associated with non-small cell lung cancer (NSCLC). The pathophysiology of HO is unknown but was recently related to enhanced levels of urine prostaglandin E2 (PGE2). Here, we report the case of a patient that presented HO in association with a resectable left upper lobe NSCLC. Following surgery and adjuvant chemotherapy, HO resolved and did not recur with development of a brain metastasis 1 year later. Interestingly, tumor cyclooxygenase-2, an enzyme responsible the synthesis of PGE2, was expressed in the primary tumor but not in the resected metastasis. PMID:26777972

  1. Expression of cyclooxygenase-2 in neoplasms of the mammary gland in bitches.

    PubMed

    Badowska-Kozakiewicz, A M; Malicka, E

    2010-01-01

    The aim of the study was to investigate the cyclooxygenase-2 expression in correlation with other neoplasm traits such as: histological type, the differentiation grade, proliferative activity, estrogenic receptor, as well as Hsp70 and p53 proteins expression. Material for the investigation comprised mammary gland tumours, collected from dogs, the patients of veterinary clinics, during surgical procedures. All together 14 adenomas, 66 complex carcinomas, 47 simple carcinomas and 6 solid carcinomas were studied. Evaluations were conducted with histopathological and immunohistochemical methods using suitable antibodies. Expression of COX-2 was observed in 95% of cancers, in case of which, the complex cancers constituted the highest percentage (48.4%). The highest expression of COX-2 was revealed in simple and complex cancers and in cancers with the 3rd degree of histological malignancy. The significant correlation between expression of COX-2 and high mean value of the mitotic index was found. The high expression of COX-2 was also correlated with the expression of protein p53 and expression of the protein Hsp 70. Obtained results suggest that cyclooxygenase-2 may be a prognostic factor, but it requires detailed clinical confirmation. PMID:20731190

  2. Novel Biphasic Role of LipoxinA4 on Expression of Cyclooxygenase-2 in Lipopolysaccharide-Stimulated Lung Fibroblasts

    PubMed Central

    Zheng, Shengxing; Wang, Qian; He, Qian; Song, Xiaorong; Ye, Duyun; Gao, Fang; Jin, Shengwei; Lian, QingQuan

    2011-01-01

    Fibroblasts are important to host defence and immunity, can also as initiators of inflammation as well. As the endogenous “braking signal”, Lipoxins can regulate anti-inflammation and the resolution of inflammation. We investigated the effect of lipoxinA4 on the expression of cyclooxygenase-2 in lipopolysaccharide-stimulated lung fibroblasts. We demonstrated that the expression of cyclooxygenase-2 protein was significantly increased and peaked initially at 6 hours, with a second increase, with maximal levels occurring 24 hours after lipopolysaccharide challenge. ProstaglandinE2 levels also peaked at 6 hours, and prostaglandinD2 levels were increased at both 6 and 24 hours. Exogenous lipoxinA4 inhibited the first peak of cyclooxygenase-2 expression as well as the production of prostaglandinE2 induced by lipopolysaccharide in a dose-dependent manner. In contrast, exogenous lipoxinA4 increased the second peak of cyclooxygenase-2 expression as well as the production of prostaglandinD2 induced by lipopolysaccharide in a dose-dependent manner. LipoxinA4 receptor mRNA expression was markedly stimulated by lipopolysaccharide but inhibited by lipoxinA4. We present evidence for a novel biphasic role of lipoxinA4 on the expression of cyclooxygenase-2 in lipopolysaccharide-stimulated lung fibroblasts, whereby LXA4 has an anti-inflammatory and proresolving activity in lung fibroblasts following LPS stimulation. PMID:21765620

  3. Kinin B2 Receptor Mediates Induction of Cyclooxygenase-2 and Is Over-Expressed In Head and Neck Squamous Cell Carcinomas

    PubMed Central

    Zhang, Weiping; Bhola, Neil; Kalyankrishna, Shailaja; Gooding, William; Hunt, Jennifer; Seethala, Raja; Grandis, Jennifer R.; Siegfried, Jill M.

    2013-01-01

    Bradykinin (BK) has been shown to promote growth and migration of head and neck squamous cell carcinoma (HNSCC) cells via epidermal growth factor receptor (EGFR) transactivation. It has also been reported that BK can cause the induction of cyclooxygenase-2 (COX-2), a pro-tumorigenic enzyme, via the MAPK (Mitogen-Activated Protein Kinase) pathway in human airway cells. To determine whether COX-2 is up-regulated by BK in HNSCC, the current study investigated BK- induced EGFR transactivation, MAPK activation, and cyclooxygenase-2 (COX-2) expression in human HNSCC cells. BK induced a concentration- and time-dependent induction of COX-2 protein in HNSCC, which was preceded by phosphorylation of EGFR and MAPK. These effects were abolished by the B2 receptor (B2R) antagonist Hoe 140 but not the B1 receptor (B1R) antagonist, Lys-[Leu8]des-Arg9-BK. COX-2 induction was accompanied by increased release of PGE2. No effect of a B1R agonist (des-Arg9-BK) on p-MAPK or COX-2 expression was observed. B2R protein was found to be expressed in all four head and neck cell lines tested. Immunohistochemical analysis and immunoblot analysis revealed that B2R, but not B1R, was significantly over-expressed in HNSCC tumors compared to levels in normal mucosa from the same patient. In HNSCC cells, the BK-induced expression of COX-2 was inhibited by the EGFR kinase inhibitor gefitinib or mitogen activated protein kinase kinases (MEK) inhibitors (PD98059 or U0126). These results suggest that EGFR and MAPK are required for COX-2 induction by BK. Up-regulation of the B2R in head and neck cancers suggests this pathway is involved in HNSCC tumorigenesis. PMID:19074839

  4. Cyclooxygenase-2 impairs treatment effects of radiotherapy for cervical cancer by inhibition of radiation-induced apoptosis

    SciTech Connect

    Ishikawa, Hitoshi . E-mail: hisikawa@med.gunma-u.ac.jp; Ohno, Tatsuya; Kato, Shingo; Wakatsuki, Masaru; Iwakawa, Mayumi; Ohta, Toshie M.S.; Imai, Takashi; Mitsuhashi, Norio; Noda, Shin-ei; Nakano, Takashi; Tsujii, Hirohiko

    2006-12-01

    Purpose: Cyclooxygenase-2 (COX-2) plays a pivotal role in regulation of radiation-induced apoptosis. The aim of this study was to analyze the relationship between COX-2 expression and postradiotherapy outcomes of patients with cervical cancer. Methods and Materials: Biopsy specimens from 47 consecutive patients who had undergone definitive radiotherapy alone or radiotherapy combined with chemotherapy between October 2002 and November 2004 were investigated. Results: The COX-2 expression rate of the pretreatment samples was 46.1% {+-} 21.0%, and the apoptotic index (AI) 1 week after start of radiotherapy was 2.1% {+-} 0.9%. There was a significant negative correlation between the pretreatment COX-2 expression and the AI during radiotherapy (r = -0.52, p = 0.0002). Complete response rates were 59% for COX-2-positive patients compared with 80% for COX-2-negative patients (p = 0.12). The 2-year local control rate for COX-2-positive patients was 71.3%, whereas the corresponding rate for COX-2-negative patients was 96.0% (p 0.06). Conclusions: To the best of our knowledge, this is the first report to prove clinically that COX-2 can make cervical squamous cell carcinomas more refractory to radiotherapy by inhibition of radiation-induced apoptosis. Furthermore, expression of COX-2 may be a good indicator to predict local tumor control after radiotherapy. Although long-term results are ultimately needed, the combination therapy of radiotherapy with use of a COX-2 inhibitor could yield improved outcomes for patients with COX-2 expressing cervical cancer.

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

    PubMed Central

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

    2016-01-01

    Fibroblasts derived from the lungs of patients with idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc) produce low levels of prostaglandin (PG) E2, due to a limited capacity to up-regulate cyclooxygenase-2 (COX-2). This deficiency contributes functionally to the fibroproliferative state, however the mechanisms responsible are incompletely understood. In the present study, we examined whether the reduced level of COX-2 mRNA expression observed in fibrotic lung fibroblasts is regulated epigenetically. The DNA methylation inhibitor, 5-aza-2′-deoxycytidine (5AZA) restored COX-2 mRNA expression by fibrotic lung fibroblasts dose dependently. Functionally, this resulted in normalization of fibroblast phenotype in terms of PGE2 production, collagen mRNA expression and sensitivity to apoptosis. COX-2 methylation assessed by bisulfite sequencing and methylation microarrays was not different in fibrotic fibroblasts compared with controls. However, further analysis of the methylation array data identified a transcriptional regulator, chromosome 8 open reading frame 4 (thyroid cancer protein 1, TC-1) (c8orf4), which is hypermethylated and down-regulated in fibrotic fibroblasts compared with controls. siRNA knockdown of c8orf4 in control fibroblasts down-regulated COX-2 and PGE2 production generating a phenotype similar to that observed in fibrotic lung fibroblasts. Chromatin immunoprecipitation demonstrated that c8orf4 regulates COX-2 expression in lung fibroblasts through binding of the proximal promoter. We conclude that the decreased capacity of fibrotic lung fibroblasts to up-regulate COX-2 expression and COX-2-derived PGE2 synthesis is due to an indirect epigenetic mechanism involving hypermethylation of the transcriptional regulator, c8orf4. PMID:26744410

  6. Investigating associations of cyclooxygenase-2 expression with angiogenesis, proliferation, macrophage and T-lymphocyte infiltration in canine melanocytic tumours.

    PubMed

    Gregório, Hugo; Raposo, Teresa P; Queiroga, Felisbina L; Prada, Justina; Pires, Isabel

    2016-08-01

    Cyclooxygenase-2 (COX-2) is known to be involved in tumour progression and has been suggested as a therapeutic target in many human and animal malignancies. A number of different pathways subjacent to cancer hallmarks are considered to be involved in COX-2-mediated tumour progression, although these are still largely undefined. Our aim is to investigate associations between COX-2 expression and angiogenesis, proliferation and the inflammatory microenvironment in canine melanocytic tumours. Understanding the involvement of COX-2 with cancer hallmarks might enable us to adapt therapeutic strategies for canine melanomas, an aggressive and often lethal malignancy with value in comparative oncology. Immunohistochemical staining of COX-2, Ki-67 (proliferation index), vascular endothelial growth factor (VEGF), factor VIII (microvessel density), CD3 (lymphocytes) and MAC387 (macrophages) was performed in 51 melanocytic tumours (31 malignant melanomas, 20 melanocytomas). Statistical associations between COX-2 and the other parameters detected were analysed. In melanocytic tumours (n=51), both COX-2 labelling extension and intensity showed a statistically significant association with angiogenesis by factor VIII, VEGF, Ki-67, CD3+ T lymphocytes and MAC387. Within malignant melanomas, COX-2 expression has shown significant associations with microvessel density (factor VIII), lymphocyte and macrophage infiltration and, considering all melanocytic tumours, COX-2 was also associated with VEGF intensity and Ki-67 cell proliferation. Our results point to a role for COX-2 in angiogenesis and in the establishment of an inflammatory microenvironment, favourable to melanoma tumour progression. Further mechanistic studies are warranted to dissect molecular pathways in which COX-2 is involved. Present evidence suggests that COX-2 inhibitors might be useful as an adjuvant treatment to hinder canine melanoma progression. PMID:27105172

  7. Inflammatory mammary carcinoma in 12 dogs: Clinical features, cyclooxygenase-2 expression, and response to piroxicam treatment

    PubMed Central

    de M. Souza, Carlos H.; Toledo-Piza, Evandro; Amorin, Renee; Barboza, Andrigo; Tobias, Karen M.

    2009-01-01

    Canine inflammatory mammary carcinoma (IMC) is a rare, locally aggressive, highly metastatic tumor that is poorly responsive to treatment. The purposes of this study were to retrospectively evaluate the history, signalment, and clinical signs of dogs with IMC; compare the outcome of affected dogs treated with traditional chemotherapy with those treated with piroxicam; evaluate Cox-2 expression of IMC cells; and correlate Cox-2 expression with outcome based on treatment. Strong cyclooxygenase-2 expression was present in all tumors. Improvement in clinical condition and disease stability was achieved in all dogs treated with piroxicam, with mean and median progression-free survival of 171 and 183 days, respectively. Median survival time of 3 dogs treated with doxorubicin-based protocols was 7 days, which was significantly less than that of dogs treated with piroxicam (median, 185 days). In conclusion, piroxicam should be considered as a single agent for the treatment of dogs with inflammatory mammary carcinoma. PMID:19436636

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  9. Two-photon uncageable enzyme inhibitors bearing targeting vectors.

    PubMed

    Anstaett, Philipp; Pierroz, Vanessa; Ferrari, Stefano; Gasser, Gilles

    2015-10-01

    The activity of two cyclooxygenase-2 enzyme inhibitors, Celecoxib and Lumiracoxib, could be suppressed by coupling to photo-labile protecting groups, so-called photocages. These groups could be further functionalized with a peptide targeting vector for specific cellular delivery. The enzyme inhibition potential of the cyclooxygenase-2 inhibitors could be regained upon two-photon excitation with tissue-transparent near-IR light at 800 nm. PMID:26314377

  10. Desferrioxamine, an iron chelator, enhances HIF-1{alpha} accumulation via cyclooxygenase-2 signaling pathway

    SciTech Connect

    Woo, Kyung Jin; Lee, Tae-Jin; Park, Jong-Wook; Kwon, Taeg Kyu . E-mail: kwontk@dsmc.or.kr

    2006-04-28

    Cyclooxygenase-2 (COX-2) is an important inducible enzyme in inflammation and is overexpressed in a variety of cancers. Evidence is rapidly accumulating that chronic inflammation may contribute to carcinogenesis through increase of cell proliferation, angiogenesis, and metastasis in a number of neoplasms, including colorectal carcinoma. In the present study, we investigated some mechanistic aspects of DFX-induced hypoxia-driven COX-2 expression. Desferrioxamine (DFX), an iron chelator, is known to upregulate inflammatory mediators. DFX induced the expression of COX-2 and accumulation of HIF-1{alpha} protein in dose-dependent manners, but hypoxia mimetic agent cobalt chloride (CoCl{sub 2}) induced accumulation of HIF-1{alpha} protein but not increase of COX-2 expression. DFX-induced increase of COX-2 expression and HIF-1{alpha} protein level was attenuated by addition of ferric citrate. This result suggested that the iron chelating function of DFX was important to induce the increase of COX-2 and HIF-1{alpha} protein. PD98059 significantly inhibited the induction of COX-2 protein and accumulation of HIF-1{alpha}, suggesting that DFX-induced increase of HIF-1{alpha} and COX-2 protein was mediated, at least in part, through the ERK signaling pathway. In addition, pretreatment with NS-398 to inhibit COX-2 activity also effectively suppressed DFX-induced HIF-1{alpha} accumulation in human colon cancer cells, providing the evidence that COX-2 plays as a regulator of HIF-1{alpha} accumulation in DFX-treated colon cancer cells. Together, our findings suggest that iron metabolism may regulate stabilization of HIF-1{alpha} protein by modulating cyclooxygenase-2 signaling pathway.

  11. Inhibition of cyclooxygenase-2 aggravates secretory phospholipase A{sub 2}-mediated progression of acute liver injury

    SciTech Connect

    Bhave, Vishakha S.; Donthamsetty, Shashikiran; Latendresse, John R.; Mehendale, Harihara M.

    2008-04-15

    Our previous study [Bhave, V. S., Donthamsetty, S., Latendresse, J. R., Muskhelishvili, L., and Mehendale, H. M. 2008-this issue. Secretory phospholipase A{sub 2} mediates progression of acute liver injury in the absence of sufficient COX-2. Toxicol Appl Pharmacol] showed that in the absence of sufficient induction and co-presence of cyclooxygenase-2 (COX-2), secretory phospholipase A{sub 2} (sPLA{sub 2}) appearing in the intercellular spaces for cleanup of post-necrotic debris seems to contribute to the progression of toxicant-initiated liver injury, possibly by hydrolysis of membrane phospholipids of hepatocytes in the perinecrotic areas. To further test our hypothesis on the protective role of COX-2, male Fisher-344 rats were administered a selective COX-2 inhibitor, NS-398, and then challenged with a moderately toxic dose of CCl{sub 4}. This led to a 5-fold increase in the susceptibility of the COX-2 inhibited rats to CCl{sub 4} hepatotoxicity and mortality. The CCl{sub 4} bioactivating enzyme CYP2E1 protein, CYP2E1 enzyme activity, and the {sup 14}CCl{sub 4}-derived radiolabel covalently bound to the liver proteins were unaffected by the COX-2 inhibitor suggesting that the increased hepatotoxic sensitivity of the COX-2 inhibited rats was not due to higher bioactivation of CCl{sub 4}. Further investigation showed that this increased mortality was due to higher plasma and hepatic sPLA{sub 2} activities, inhibited PGE{sub 2} production, and progression of liver injury as compared to the non-intervened rats{sub .} In conclusion, inhibition of COX-2 mitigates the tissue protective mechanisms associated with COX-2 induction, which promotes sPLA{sub 2}-mediated progression of liver injury in an acute liver toxicity model. Because increased sPLA{sub 2} activity in the intercellular space is associated with increased progression of injury, and induced COX-2 is associated with hepatoprotection, ratios of hepatic COX-2 and sPLA{sub 2} activities may turn out to be a

  12. Altered mRNA editing and expression of ionotropic glutamate receptors after kainic acid exposure in cyclooxygenase-2 deficient mice.

    PubMed

    Caracciolo, Luca; Barbon, Alessandro; Palumbo, Sara; Mora, Cristina; Toscano, Christopher D; Bosetti, Francesca; Barlati, Sergio

    2011-01-01

    Kainic acid (KA) binds to the AMPA/KA receptors and induces seizures that result in inflammation, oxidative damage and neuronal death. We previously showed that cyclooxygenase-2 deficient (COX-2(-/-)) mice are more vulnerable to KA-induced excitotoxicity. Here, we investigated whether the increased susceptibility of COX-2(-/-) mice to KA is associated with altered mRNA expression and editing of glutamate receptors. The expression of AMPA GluR2, GluR3 and KA GluR6 was increased in vehicle-injected COX-2(-/-) mice compared to wild type (WT) mice in hippocampus and cortex, whereas gene expression of NMDA receptors was decreased. KA treatment decreased the expression of AMPA, KA and NMDA receptors in the hippocampus, with a significant effect in COX-2(-/-) mice. Furthermore, we analyzed RNA editing levels and found that the level of GluR3 R/G editing site was selectively increased in the hippocampus and decreased in the cortex in COX-2(-/-) compared with WT mice. After KA, GluR4 R/G editing site, flip form, was increased in the hippocampus of COX-2(-/-) mice. Treatment of WT mice with the COX-2 inhibitor celecoxib for two weeks decreased the expression of AMPA/KA and NMDAR subunits after KA, as observed in COX-2(-/-) mice. After KA exposure, COX-2(-/-) mice showed increased mRNA expression of markers of inflammation and oxidative stress, such as cytokines (TNF-α, IL-1β and IL-6), inducible nitric oxide synthase (iNOS), microglia (CD11b) and astrocyte (GFAP). Thus, COX-2 gene deletion can exacerbate the inflammatory response to KA. We suggest that COX-2 plays a role in attenuating glutamate excitotoxicity by modulating RNA editing of AMPA/KA and mRNA expression of all ionotropic glutamate receptor subunits and, in turn, neuronal excitability. These changes may contribute to the increased vulnerability of COX-2(-/-) mice to KA. The overstimulation of glutamate receptors as a consequence of COX-2 gene deletion suggests a functional coupling between COX-2 and the

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

    SciTech Connect

    Simões, Maylla Ronacher; Aguado, Andrea; Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice; Zhenyukh, Olha; Briones, Ana María; Alonso, María Jesús; Vassallo, Dalton Valentim; Salaices, Mercedes

    2015-03-01

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

  14. A cyclooxygenase-2 homologue encoded by rhesus cytomegalovirus is a determinant for endothelial cell tropism.

    PubMed

    Rue, Cary A; Jarvis, Michael A; Knoche, Amber J; Meyers, Heather L; DeFilippis, Victor R; Hansen, Scott G; Wagner, Markus; Früh, Klaus; Anders, David G; Wong, Scott W; Barry, Peter A; Nelson, Jay A

    2004-11-01

    Cyclooxygenase-2 (COX-2) is a cellular enzyme in the eicosanoid synthetic pathway that mediates the synthesis of prostaglandins from arachidonic acid. The eicosanoids function as critical regulators of a number of cellular processes, including the acute and chronic inflammatory response, hemostasis, and the innate immune response. Human cytomegalovirus (HCMV), which does not encode a viral COX-2 isoform, has been shown to induce cellular COX-2 expression. Importantly, although the precise role of COX-2 in CMV replication is unknown, COX-2 induction was shown to be critical for normal HCMV replication. In an earlier study, we identified an open reading frame (Rh10) within the rhesus cytomegalovirus (RhCMV) genome that encoded a putative protein (designated vCOX-2) with high homology to cellular COX-2. In the current study, we show that vCOX-2 is expressed with early-gene kinetics during RhCMV infection, resulting in production of a 70-kDa protein. Consistent with the expression of a viral COX-2 isoform, cellular COX-2 expression was not induced during RhCMV infection. Finally, analysis of growth of recombinant RhCMV with vCOX-2 deleted identified vCOX-2 as a critical determinant for replication in endothelial cells. PMID:15507640

  15. A Cyclooxygenase-2 Homologue Encoded by Rhesus Cytomegalovirus Is a Determinant for Endothelial Cell Tropism

    PubMed Central

    Rue, Cary A.; Jarvis, Michael A.; Knoche, Amber J.; Meyers, Heather L.; DeFilippis, Victor R.; Hansen, Scott G.; Wagner, Markus; Früh, Klaus; Anders, David G.; Wong, Scott W.; Barry, Peter A.; Nelson, Jay A.

    2004-01-01

    Cyclooxygenase-2 (COX-2) is a cellular enzyme in the eicosanoid synthetic pathway that mediates the synthesis of prostaglandins from arachidonic acid. The eicosanoids function as critical regulators of a number of cellular processes, including the acute and chronic inflammatory response, hemostasis, and the innate immune response. Human cytomegalovirus (HCMV), which does not encode a viral COX-2 isoform, has been shown to induce cellular COX-2 expression. Importantly, although the precise role of COX-2 in CMV replication is unknown, COX-2 induction was shown to be critical for normal HCMV replication. In an earlier study, we identified an open reading frame (Rh10) within the rhesus cytomegalovirus (RhCMV) genome that encoded a putative protein (designated vCOX-2) with high homology to cellular COX-2. In the current study, we show that vCOX-2 is expressed with early-gene kinetics during RhCMV infection, resulting in production of a 70-kDa protein. Consistent with the expression of a viral COX-2 isoform, cellular COX-2 expression was not induced during RhCMV infection. Finally, analysis of growth of recombinant RhCMV with vCOX-2 deleted identified vCOX-2 as a critical determinant for replication in endothelial cells. PMID:15507640

  16. Transcriptional activation of cyclooxygenase-2 by tumor suppressor p53 requires nuclear factor-kappaB.

    PubMed

    Benoit, V; de Moraes, E; Dar, N A; Taranchon, E; Bours, V; Hautefeuille, A; Tanière, P; Chariot, A; Scoazec, J-Y; de Moura Gallo, C V; Merville, M-P; Hainaut, P

    2006-09-21

    Overexpression of cyclooxygenase-2 (Cox-2) is thought to exert antiapoptotic effects in cancer. Here we show that the tumor suppressor p53 upregulated Cox-2 in esophageal and colon cancer cell lines by inducing the binding of nuclear factor-kappaB (NF-kappaB) to its response element in the COX-2 promoter. Inhibition of NF-kappaB prevented p53 induction of Cox-2 expression. Cooperation between p53 and NF-kappaB was required for activation of COX-2 promoter in response to daunomycin, a DNA-damaging agent. Pharmacological inhibition of Cox-2 enhanced apoptosis in response to daunomycin, in particular in cells containing active p53. In esophageal cancer, there was a correlation between Cox-2 expression and wild-type TP53 in Barrett's esophagus (BE) and in adenocarcinoma, but not in squamous cell carcinoma (P<0.01). These results suggest that p53 and NF-kappaB cooperate in upregulating Cox-2 expression, promoting cell survival in inflammatory precursor lesions such as BE. PMID:16682957

  17. Paeoniflorin ameliorates rheumatoid arthritis in rat models through oxidative stress, inflammation and cyclooxygenase 2

    PubMed Central

    JIA, ZHILIN; HE, JIAO

    2016-01-01

    Paeoniflorin has anti-inflammatory, anti-allergy, immune regulatory and pain-relieving effects, amongst other roles. However, the mechanisms underlying the protective effects of paeoniflorin on rheumatoid arthritis (RA) remain under investigation; the objective of the current study was to evaluate these protective effects in the context of an RA model. Rats were randomly divided into 5 groups, as follows: The control group, the RA rat model group, and the paeoniflorin groups, in which paeoniflorin was administered at concentrations of 5, 10 and 20 mg/kg for 3 weeks. The pain thresholds and arthritic symptoms of the RA rats were measured. Oxidative stress and inflammatory cytokines were also analyzed and western blot analysis was used to evaluate cyclooxygenase-2 (COX-2) protein expression levels. Paeoniflorin significantly increased the pain threshold and decreased the arthritic symptoms in the RA rat model. Notably, paeoniflorin reduced the malondialdehyde concentration and increased the activity of superoxide dismutase, catalase and glutathione peroxidase. Furthermore, paeoniflorin attenuated the activity of nuclear factor-κB p65 unit, tumor necrosis factor-α, interleukin (IL)-1β and IL-6, and reduced the COX-2 protein expression level. The present study indicates that paeoniflorin ameliorates disease in rat models of RA through oxidative stress, inflammation and alterations to COX-2 expression. PMID:26893662

  18. Meta-analysis of cyclooxygenase-2 (COX-2) 765G>C polymorphism and Alzheimer's disease.

    PubMed

    Su, Jianhua; Wen, Shihong; Zhu, Jinlong; Liu, Ruiping; Yang, Jinsong

    2016-09-01

    The cyclooxygenase-2 (COX-2) 765G>C polymorphism has been extensively investigated for association with Alzheimer's disease (AD). However, results of different studies have been inconsistent. The aim of the present meta-analysis was to evaluate the association between the 765G>C polymorphism of the COX-2 gene and susceptibility to AD. We searched all related subjects in PubMed, Embase, SinoMed, and China Knowledge Resource Integrated Database and identified seven studies that reported a relationship between the COX-2 765G>C polymorphism and AD. A total of 1260 cases and 1112 controls were included in the seven studies. Our data suggest that the COX-2 765G>C polymorphism may decrease the risk of AD in five genetic models. As a result, this meta-analysis suggests the 765G>C polymorphism of the COX-2 gene may be a protective factor for AD. As our sample size was limited, large-scale, well-designed studies are necessary to validate the association between the COX-2 765G>C polymorphism and AD. PMID:27443496

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

    PubMed

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

    2016-07-29

    Excessive adipocyte lipolysis generates lipid mediators and triggers inflammation in adipose tissue. However, the specific roles of lipolysis-generated mediators in adipose inflammation remain to be elucidated. In the present study, cultured 3T3-L1 adipocytes were treated with isoproterenol to activate lipolysis and the fatty acyl lipidome of released lipids was determined by using LC-MS/MS. We observed that β-adrenergic activation elevated levels of approximately fifty lipid species, including metabolites of cyclooxygenases, lipoxygenases, epoxygenases, and other sources. Moreover, we found that β-adrenergic activation induced cyclooxygenase 2 (COX-2), not COX-1, expression in a manner that depended on activation of hormone-sensitive lipase (HSL) in cultured adipocytes and in the epididymal white adipose tissue (EWAT) of C57BL/6 mice. We found that lipolysis activates the JNK/NFκB signaling pathway and inhibition of the JNK/NFκB axis abrogated the lipolysis-stimulated COX-2 expression. In addition, pharmacological inhibition of COX-2 activity diminished levels of COX-2 metabolites during lipolytic activation. Inhibition of COX-2 abrogated the induction of CCL2/MCP-1 expression by β-adrenergic activation and prevented recruitment of macrophage/monocyte to adipose tissue. Collectively, our data indicate that excessive adipocyte lipolysis activates the JNK/NFκB pathway leading to the up-regulation of COX-2 expression and recruitment of inflammatory macrophages. PMID:27246851

  20. Influenza A viruses suppress cyclooxygenase-2 expression by affecting its mRNA stability

    PubMed Central

    Dudek, Sabine Eva; Nitzsche, Katja; Ludwig, Stephan; Ehrhardt, Christina

    2016-01-01

    Infection with influenza A viruses (IAV) provokes activation of cellular defence mechanisms contributing to the innate immune and inflammatory response. In this process the cyclooxygenase-2 (COX-2) plays an important role in the induction of prostaglandin-dependent inflammation. While it has been reported that COX-2 is induced upon IAV infection, in the present study we observed a down-regulation at later stages of infection suggesting a tight regulation of COX-2 by IAV. Our data indicate the pattern-recognition receptor RIG-I as mediator of the initial IAV-induced COX-2 synthesis. Nonetheless, during on-going IAV replication substantial suppression of COX-2 mRNA and protein synthesis could be detected, accompanied by a decrease in mRNA half-life. Interestingly, COX-2 mRNA stability was not only imbalanced by IAV replication but also by stimulation of cells with viral RNA. Our results reveal tristetraprolin (TTP), which is known to bind COX-2 mRNA and promote its rapid degradation, as regulator of COX-2 expression in IAV infection. During IAV replication and viral RNA accumulation TTP mRNA synthesis was induced, resulting in reduced COX-2 levels. Accordingly, the down-regulation of TTP resulted in increased COX-2 protein expression after IAV infection. These findings indicate a novel IAV-regulated cellular mechanism, contributing to the repression of host defence and therefore facilitating viral replication. PMID:27265729

  1. Induction of cyclooxygenase-2 in monocyte/macrophage by mucins secreted from colon cancer cells

    PubMed Central

    Inaba, Takaaki; Sano, Hajime; Kawahito, Yutaka; Hla, Timothy; Akita, Kaoru; Toda, Munetoyo; Yamashina, Ikuo; Inoue, Mizue; Nakada, Hiroshi

    2003-01-01

    Up-regulation of cyclooxygenase-2 (COX-2) and overproduction of prostaglandins have been implicated in the initiation and/or progression of colon cancer. However, it is uncertain in which cells and how COX-2 is induced initially in the tumor microenvironment. We found that a conditioned medium of the colon cancer cell line, LS 180, contained a factor to induce COX-2 in human peripheral blood mononuclear cells. This factor was purified biochemically and revealed to be mucins. A small amount of mucins (≈100 ng of protein per ml) could elevate prostaglandin E2 production by monocytes. The mucins induced COX-2 mRNA and protein levels of monocytes in a dose- and time-dependent manner, indicating a COX-2-mediated pathway. We also have examined immunohistochemically the localization of COX-2 protein and mucins in human colorectal cancer tissues. It is noteworthy that COX-2-expressing macrophages were located around the region in which mucins were detectable, suggesting that COX-2 also was induced by mucins in vivo. These results suggest that mucins produced by colon cancer cells play a critical role in the initial induction of COX-2 in the tumor microenvironment. PMID:12598658

  2. Inhibition of cyclooxygenase-2 impacts chondrocyte hypertrophic differentiation during endochondral ossification.

    PubMed

    Welting, T J M; Caron, M M J; Emans, P J; Janssen, M P F; Sanen, K; Coolsen, M M E; Voss, L; Surtel, D A M; Cremers, A; Voncken, J W; van Rhijn, L W

    2011-01-01

    Skeletogenesis and bone fracture healing involve endochondral ossification, a process during which cartilaginous primordia are gradually replaced by bone tissue. In line with a role for cyclooxygenase-2 (COX-2) in the endochondral ossification process, non-steroidal anti-inflammatory drugs (NSAIDs) were reported to negatively affect bone fracture healing due to impaired osteogenesis. However, a role for COX-2 activity in the chondrogenic phase of endochondral ossification has not been addressed before. We show that COX-2 activity fulfils an important regulatory function in chondrocyte hypertrophic differentiation. Our data reveal essential cross-talk between COX-2 and bone morphogenic protein-2 (BMP-2) during chondrocyte hypertrophic differentiation. BMP-2 mediated chondrocyte hypertrophy is associated with increased COX-2 expression and pharmacological inhibition of COX-2 activity by NSAIDs (e.g., Celecoxib) decreases hypertrophic differentiation in various chondrogenic models in vitro and in vivo, while leaving early chondrogenic development unaltered. Our findings demonstrate that COX-2 activity is a novel factor partaking in chondrocyte hypertrophy in the context of endochondral ossification and these observations provide a novel etiological perspective on the adverse effects of NSAIDs on bone fracture healing and have important implications for the use of NSAIDs during endochondral skeletal development. PMID:22183916

  3. Design, Synthesis, and Evaluation of an (18)F-Labeled Radiotracer Based on Celecoxib-NBD for Positron Emission Tomography (PET) Imaging of Cyclooxygenase-2 (COX-2).

    PubMed

    Kaur, Jatinder; Tietz, Ole; Bhardwaj, Atul; Marshall, Alison; Way, Jenilee; Wuest, Melinda; Wuest, Frank

    2015-10-01

    A series of novel fluorine-containing cyclooxygenase-2 (COX-2) inhibitors was designed and synthesized based on the previously reported fluorescent COX-2 imaging agent celecoxib-NBD (3; NBD=7-nitrobenzofurazan). In vitro COX-1/COX-2 inhibitory data show that N-(4-fluorobenzyl)-4-(5-p-tolyl-3-trifluoromethylpyrazol-1-yl)benzenesulfonamide (5; IC50 =0.36 μM, SI>277) and N-fluoromethyl-4-(5-p-tolyl-3-trifluoromethylpyrazol-1-yl)benzenesulfonamide (6; IC50 =0.24 μM, SI>416) are potent and selective COX-2 inhibitors. Compound 5 was selected for radiolabeling with the short-lived positron emitter fluorine-18 ((18) F) and evaluated as a positron emission tomography (PET) imaging agent. Radiotracer [(18) F]5 was analyzed in vitro and in vivo using human colorectal cancer model HCA-7. Although radiotracer uptake into COX-2-expressing HCA-7 cells was high, no evidence for COX-2-specific binding was found. Radiotracer uptake into HCA-7 tumors in vivo was low and similar to that of muscle, used as reference tissue. PMID:26287271

  4. 2,2',4,4'-Tetrachlorobiphenyl upregulates cyclooxygenase-2 in HL-60 cells via p38 mitogen-activated protein kinase and NF-{kappa}B

    SciTech Connect

    Bezdecny, Steven A.; Karmaus, Peer; Roth, Robert A.; Ganey, Patricia E. . E-mail: ganey@msu.edu

    2007-06-15

    Polychlorinated biphenyls (PCBs) are ubiquitous, persistent environmental contaminants that affect a number of cellular systems, including neutrophils. Among the effects caused by the noncoplanar PCB 2,2',4,4'-tetrachlorobiphenyl (2244-TCB) in granulocytic HL-60 cells are increases in superoxide anion production, activation of phospholipase A{sub 2} with subsequent release of arachidonic acid (AA) and upregulation of the inflammatory gene cyclooxygenase-2 (COX-2). The objective of this study was to determine the signal transduction pathways involved in the upregulation of COX-2 by 2244-TCB. Treatment of HL-60 cells with 2244-TCB led to increased expression of COX-2 mRNA. This increase was prevented by the transcriptional inhibitor actinomycin D in cells pretreated with 2244-TCB for 10 min. The increase in COX-2 mRNA was associated with release of {sup 3}H-AA, phosphorylation of p38 and extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinases, increased levels of nuclear NF-{kappa}B and increased superoxide anion production. Bromoenol lactone, an inhibitor of the calcium-independent phospholipase A{sub 2}, reduced {sup 3}H-AA release but had no effect on COX-2 mRNA, protein or activity. Pretreatment with SB-202190 or SB-203580, inhibitors of the p38 MAP kinase pathway, prevented the 2244-TCB-mediated induction of COX-2 and phosphorylation of p38 and ERK MAP kinases. These inhibitors did not alter {sup 3}H-AA release. Treatment with PD 98059 or U 0126, inhibitors of the MAP/ERK (MEK) pathway, prevented the 2244-TCB-mediated activation of ERK but had no effect on COX-2 induction or p38 phosphorylation. 2244-TCB treatment did not affect c-Jun N-terminal kinase (JNK) phosphorylation. 2244-TCB exposure increased the amount of nuclear NF-{kappa}B. This increase was prevented by pretreatment with p38 MAP kinase inhibitors, but not by pretreatment with MEK inhibitors. Pretreatment with inhibitors of NF-{kappa}B prevented the 2244-TCB

  5. Importance of adipocyte cyclooxygenase-2 and prostaglandin E2-prostaglandin E receptor 3 signaling in the development of obesity-induced adipose tissue inflammation and insulin resistance.

    PubMed

    Chan, Pei-Chi; Hsiao, Fone-Ching; Chang, Hao-Ming; Wabitsch, Martin; Hsieh, Po Shiuan

    2016-06-01

    We examined the involvement of adipocyte cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2)-prostaglandin E receptor (EP)3-mediated signaling during hypertrophy and hypoxia in the development of obesity-associated adipose tissue (AT) inflammation and insulin resistance. The experiments were conducted with high-fat diet (HFD)-induced obese rats, db/db mice, human subjects, and 3T3-L1 and the human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes; the groups were treated with selective inhibitors of COX-2 [celecoxib 30 mg/kg, half maximal inhibitory concentration (IC50) ≈ 0.04 µM] and EP3 (L-798106 100 µg/kg, IC50 ≈ 0.5 µM) or a short interfering RNA. There were strong, positive correlations between adipocyte COX-2 and EP3 gene expressions and the AT TNF-α and monocyte chemotactic protein-1 contents and the homeostatic model assessment for insulin resistance in HFD-induced obese rats, as well as body mass index in human subjects. Treatment with COX-2 and EP3 inhibitors significantly reversed AT inflammatory gene and protein expressions (-50%) and impaired glucose and insulin tolerance in db/db mice. COX-2 inhibition diminished the chemotaxis of adipocytes isolated from HFD rats to macrophages and T cells. Targeting inhibition of adipocyte COX-2 and EP3 during hypertrophy and hypoxia reversed the release of the augmented proinflammatory adipokines and the diminished adiponectin and also suppressed NF-κB and hypoxia-inducible factor-1α transcription activation. These findings suggest that adipocyte COX-2 PGE2-EP3-mediated signaling is crucially involved in the development of obesity-associated AT inflammation and insulin resistance.-Chan, P.-C., Hsiao, F.-C., Chang, H.-M., Wabitsch, M., Hsieh, P. S. Importance of adipocyte cyclooxygenase-2 and prostaglandin E2-prostaglandin E receptor 3 signaling in the development of obesity-induced adipose tissue inflammation and insulin resistance. PMID:26932930

  6. Lactoferrin from Camelus dromedarius Inhibits Nuclear Transcription Factor-kappa B Activation, Cyclooxygenase-2 Expression and Prostaglandin E2 Production in Stimulated Human Chondrocytes

    PubMed Central

    Rasheed, Naila; Alghasham, Abdullah; Rasheed, Zafar

    2016-01-01

    Background: Osteoarthritis (OA) is a progressive joint disorder, which remains the leading cause of chronic disability in aged people. Nuclear factor-kappa B (NF)-κB is a major cellular event in OA and its activation by interleukin-1β (IL-1β) plays a critical role in cartilage breakdown in these patients. Objective: In this study, we examined the effect of lactoferrin on NF-κB activation, cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production in stimulated human articular chondrocytes. Materials and Methods: Human chondrocytes were derived from OA articular cartilage and treated with camel lactoferrin and then stimulated with IL-1β. Gene expression was determined by TaqMan assays and protein expression was studied by Western immunoblotting. NF-κB activity and PGE2 levels were determined by ELISA based assays. NF-κB activity was also determined by treatment of chondrocytes with NF-κB specific inhibitor Bay 11–7082. Results: Lactoferrin inhibited IL-1β-induced activation and nuclear translocation of NF-κB p65 in human OA chondrocytes. Lactoferrin also inhibited mRNA/protein expression of COX-2 and production of PGE2. Moreover, Bay 11–7082 also inhibited IL-1β-induced expression of COX-2 and production of PGE2. The inhibitory effect of lactoferrin on the IL-1β induced expression of COX-2 or production of PGE2 was mediated at least in part via suppression of NF-κB activation. Conclusions: Our data determine camel lactoferrin as a novel inhibitor of IL-1β-induced activation of NF-κB signaling events and production of cartilage-degrading molecule PGE2 via inhibition of COX-2 expressions. These results may have important implications for the development of novel therapeutic strategies for the prevention/treatment of OA and other degenerative/inflammatory diseases. SUMMARY Lactoferrin shows anti-arthritic activity in IL-1β stimulated primary human chondrocytes.Lactoferrin inhibits IL-1β-induced NF-κB activation.Lactoferrin inhibits

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

    PubMed Central

    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

    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. PMID:24988319

  8. Cyclooxygenase-2 expression in hepatocytes attenuates non-alcoholic steatohepatitis and liver fibrosis in mice.

    PubMed

    Motiño, Omar; Agra, Noelia; Brea Contreras, Rocío; Domínguez-Moreno, Marina; García-Monzón, Carmelo; Vargas-Castrillón, Javier; Carnovale, Cristina E; Boscá, Lisardo; Casado, Marta; Mayoral, Rafael; Valdecantos, M Pilar; Valverde, Ángela M; Francés, Daniel E; Martín-Sanz, Paloma

    2016-09-01

    Cyclooxygenase-2 (COX-2) is involved in different liver diseases but little is known about the significance of COX-2 in the development and progression of non-alcoholic steatohepatitis (NASH). This study was designed to elucidate the role of COX-2 expression in hepatocytes in the pathogenesis of steatohepatitis and hepatic fibrosis. In the present work, hepatocyte-specific COX-2 transgenic mice (hCOX-2-Tg) and their wild-type (Wt) littermates were either fed methionine-and-choline deficient (MCD) diet to establish an experimental non-alcoholic steatohepatitis (NASH) model or injected with carbon tetrachloride (CCl4) to induce liver fibrosis. In our animal model, hCOX-2-Tg mice fed MCD diet showed lower grades of steatosis, ballooning and inflammation than Wt mice, in part by reduced recruitment and infiltration of hepatic macrophages, with a corresponding decrease in serum levels of pro-inflammatory cytokines. Furthermore, hCOX-2-Tg mice showed a significant attenuation of the MCD diet-induced increase in oxidative stress and hepatic apoptosis observed in Wt mice. Even more, hCOX-2-Tg mice treated with CCl4 had significantly lower stages of fibrosis and less hepatic content of collagen, hydroxyproline and pro-fibrogenic markers than Wt controls. Collectively, our data indicates that constitutive hepatocyte COX-2 expression ameliorates NASH and liver fibrosis development in mice by reducing inflammation, oxidative stress and apoptosis and by modulating activation of hepatic stellate cells, respectively, suggesting a possible protective role for COX-2 induction in NASH/NAFLD progression. PMID:27321932

  9. Expression of Cyclooxygenase-2 in Human Transitional Cell Carcinoma of the Urinary Bladder

    PubMed Central

    Ristimäki, Ari; Nieminen, Outi; Saukkonen, Kirsi; Hotakainen, Kristina; Nordling, Stig; Haglund, Caj

    2001-01-01

    Recent studies suggest that expression of cyclooxygenase-2 (Cox-2) is elevated in transitional cell carcinoma (TCC) of the urinary bladder and that inhibition of Cox-2 activity suppresses bladder cancer in experimental animal models. We have investigated the expression of Cox-2 protein in human TCCs (n = 85), in in situ carcinomas (Tis) of the urinary bladder (n = 17), and in nonneoplastic urinary bladder samples (n = 16) using immunohistochemistry. Cox-2 immunoreactivity was detected in 66% (67 of 102) of the carcinomas, whereas only 25% (4 of 16) of the nonneoplastic samples were positive (P < 0.005). Cox-2 immunoreactivity localized to neoplastic cells in the carcinoma samples. The rate of positivity was the same in invasive (T1–3; 70%, n = 40) and in noninvasive (Tis and Ta; 65%, n = 62) carcinomas, but noninvasive tumors had a higher frequency (32%) of homogenous pattern of staining (>90% of the tumor cells positive) than the invasive carcinomas (10%) (P < 0.05). However, several invasive TCCs exhibited the strongest intensity of Cox-2 staining in the invading cells, whereas other parts of the tumor were virtually negative. Finally, strong Cox-2 positivity was also found in nonneoplastic ulcerations (2 of 2) and in inflammatory pseudotumors (2 of 2), in which the immunoreactivity localized to the nonepithelial cells. Taken together, our data suggest that Cox-2 is highly expressed in noninvasive bladder carcinomas, whereas the highest expression of invasive tumors associated with the invading cells, and that Cox-2 may also have a pathophysiological role in nonneoplastic conditions of the urinary bladder, such as ulcerations and inflammatory pseudotumors. PMID:11238034

  10. Neuronal NOS and cyclooxygenase-2 contribute to DNA damage in a mouse model of Parkinson disease.

    PubMed

    Hoang, Tuan; Choi, Dong-Kug; Nagai, Makiko; Wu, Du-Chu; Nagata, Tetsuya; Prou, Delphine; Wilson, Glenn L; Vila, Miquel; Jackson-Lewis, Vernice; Dawson, Valina L; Dawson, Ted M; Chesselet, Marie-Françoise; Przedborski, Serge

    2009-10-01

    DNA damage is a proposed pathogenic factor in neurodegenerative disorders such as Parkinson disease. To probe the underpinning mechanism of such neuronal perturbation, we sought to produce an experimental model of DNA damage. We thus first assessed DNA damage by in situ nick translation and emulsion autoradiography in the mouse brain after administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 4 x 20 mg/kg, ip, every 2 h), a neurotoxin known to produce a model of Parkinson disease. Here we show that DNA strand breaks occur in vivo in this mouse model of Parkinson disease with kinetics and a topography that parallel the degeneration of substantia nigra neurons, as assessed by FluoroJade labeling. Previously, nitric oxide synthase and cyclooxygenase-2 (Cox-2) were found to modulate MPTP-induced dopaminergic neuronal death. We thus assessed the contribution of these enzymes to DNA damage in mice lacking neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), or Cox-2. We found that the lack of Cox-2 and nNOS activities but not of iNOS activity attenuated MPTP-related DNA damage. We also found that not only nuclear, but also mitochondrial, DNA is a target for the MPTP insult. These results suggest that the loss of genomic integrity can be triggered by the concerted actions of nNOS and Cox-2 and provide further support to the view that DNA damage may contribute to the neurodegenerative process in Parkinson disease. PMID:19616617

  11. Role of the cyclooxygenase 2-thromboxane pathway in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced decrease in mesencephalic vein blood flow in the zebrafish embryo

    SciTech Connect

    Teraoka, Hiroki Kubota, Akira; Dong, Wu; Kawai, Yusuke; Yamazaki, Koji; Mori, Chisato; Harada, Yoshiteru; Peterson, Richard E.; Hiraga, Takeo

    2009-01-01

    Previously, we reported that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) evoked developmental toxicity required activation of aryl hydrocarbon receptor type 2 (AHR2), using zebrafish embryos. However, the downstream molecular targets of AHR2 activation are largely unknown and are the focus of the present investigation. TCDD induces cyclooxygenase 2 (COX2), a rate-limiting enzyme for prostaglandin synthesis in certain cells. In the present study, we investigated the role of the COX2-thromboxane pathway in causing a specific endpoint of TCDD developmental toxicity in the zebrafish embryo, namely, a decrease in regional blood flow in the dorsal midbrain. It was found that the TCDD-induced reduction in mesencephalic vein blood flow was markedly inhibited by selective COX2 inhibitors, NS-398 and SC-236, and by a general COX inhibitor, indomethacin, but not by a selective COX1 inhibitor, SC-560. Gene knock-down of COX2 by two different types of morpholino antisense oligonucleotides, but not by their negative homologs, also protected the zebrafish embryos from mesencephalic vein circulation failure caused by TCDD. This inhibitory effect of TCDD on regional blood flow in the dorsal midbrain was also blocked by selective antagonists of the thromboxane receptor (TP). Treatment of control zebrafish embryos with a TP agonist also caused a reduction in mesencephalic vein blood flow and it too was blocked by a TP antagonist, without any effect on trunk circulation. Finally, gene knock-down of thromboxane A synthase 1 (TBXS) with morpholinos but not by the morpholinos' negative homologs provided significant protection against TCDD-induced mesencephalic circulation failure. Taken together, these results point to a role of the prostanoid synthesis pathway via COX2-TBXS-TP in the local circulation failure induced by TCDD in the dorsal midbrain of the zebrafish embryo.

  12. Cyclooxygenase-2 expression is up-regulated by 2-aminobiphenyl in a ROS and MAPK-dependent signaling pathway in a bladder cancer cell line.

    PubMed

    Chen, Chien-Cheng; Cheng, Yu-Yang; Chen, Ssu-Ching; Tuan, Yen-Fan; Chen, Yun-Ju; Chen, Chien-Yen; Chen, Lei-Chin

    2012-03-19

    Overexposure to biphenyl amine compounds, which are found in smoke and azo-dyes, is linked to the occurrence of bladder cancer. However, the molecular mechanisms of biphenyl amine compound-induced bladder cancer are still unclear. Many studies have demonstrated that overexpression of cyclooxygenase-2 (COX-2) in neoplastic lesions is associated with carcinogenesis. In this study, we have demonstrated that 2-aminobiphenyl (2-ABP) up-regulated the expression of COX-2 in a dose- and time-dependent manner in TSGH-8301 bladder cancer cells. This 2-ABP-induced COX-2 expression was attenuated by ROS scavenger NAC and NADPH oxidase inhibitors apocynin and DPI. The p22phox subunit of NADPH oxidase, but not p67, and Nox2 was up-regulated by 2-ABP. Knocking down p22phox by siRNA significantly reduced 2-ABP-induced COX-2 expression. Furthermore, 2-ABP also activated the ERK/JNK-AP1 pathways, and this effect was also abolished by NADPH oxidase inhibitors. Blocking the ERK/JNK-AP1 signaling pathways by pharmacological inhibitors attenuated 2-ABP-induced COX-2 expression. Overexpression of the upstream ERK activator MEK1 significantly and consistently increased 2-ABP-mediated COX-2 expression. Transfection of a dominant negative c-Jun mutant, TAM-67, blocked 2-ABP-mediated COX-2 expression, demonstrating that c-Jun was responsible for the transcriptional activation. Taken together, these results demonstrate that 2-ABP induces the carcinogenic factor COX-2 and that this induction is mediated through NADPH oxidase-derived ROS-dependent JNK/ERK-AP-1 pathways. PMID:22288910

  13. Antineoplastic effect of a novel chemopreventive agent, neokestose, on the Caco-2 cell line via inhibition of expression of nuclear factor-κB and cyclooxygenase-2.

    PubMed

    Lee, Shun-Mei; Chang, Jan-Yi; Wu, Jiann-Shing; Sheu, Dey-Chyi

    2015-07-01

    Neokestose is a 6G-fructooligosaccharide (FOS) and an important prebiotic. When FOS are ingested by patients with colorectal cancer, they may come into contact with cancer cells prior to being fermented by bifidobacteria in the colon. In the present study, the effects of neokestose on cell proliferation, cell cycle and apoptosis of the colorectal cancer cell line Caco-2 were investigated to evaluate its anti-cancer effect. An MTT assay showed that neokestose-treated Caco-2 cells exhibited a significant and dose-dependent loss of viability. Flow cytometric analysis indicated that the sub-G1 population of Caco-2 cells was significantly increased following treatment with neokestose, and the percentage of Caco-2 cells in the stage of late apoptosis was also significantly increased in a dose-dependent manner. Western blot analysis showed that the overexpression of nuclear factor-κB, a central molecule responsible for the transition from inflammation to cancer, and cyclooxygenase-2, an important enzyme in colorectal tumorigenesis, in colorectal carcinoma cells was inhibited by neokestose. Accordingly, the present study provided in vitro evidence that neokestose may be used as a dietary chemopreventive agent, whose application is more rational than that of COX-2 inhibitors or aspirin for preventing colorectal cancer. PMID:25815878

  14. Caveolin-1-mediated suppression of cyclooxygenase-2 via a beta-catenin-Tcf/Lef-dependent transcriptional mechanism reduced prostaglandin E2 production and survivin expression.

    PubMed

    Rodriguez, Diego A; Tapia, Julio C; Fernandez, Jaime G; Torres, Vicente A; Muñoz, Nicolas; Galleguillos, Daniela; Leyton, Lisette; Quest, Andrew F G

    2009-04-01

    Augmented expression of cyclooxygenase-2 (COX-2) and enhanced production of prostaglandin E(2) (PGE(2)) are associated with increased tumor cell survival and malignancy. Caveolin-1 is a scaffold protein that has been proposed to function as a tumor suppressor in human cancer cells, although mechanisms underlying this ability remain controversial. Intriguingly, the possibility that caveolin-1 regulates the expression of COX-2 has not been explored. Here we show that augmented caveolin-1 expression in cells with low basal levels of this protein, such as human colon cancer (HT29, DLD-1), breast cancer (ZR75), and embryonic kidney (HEK293T) cells reduced COX-2 mRNA and protein levels and beta-catenin-Tcf/Lef and COX-2 gene reporter activity, as well as the production of PGE(2) and cell proliferation. Moreover, COX-2 overexpression or PGE(2) supplementation increased levels of the inhibitor of apoptosis protein survivin by a transcriptional mechanism, as determined by PCR analysis, survivin gene reporter assays and Western blotting. Furthermore, addition of PGE(2) to the medium prevented effects attributed to caveolin-1-mediated inhibition of beta-catenin-Tcf/Lef-dependent transcription. Finally, PGE(2) reduced the coimmunoprecipitation of caveolin-1 with beta-catenin and their colocalization at the plasma membrane. Thus, by reducing COX-2 expression, caveolin-1 interrupts a feedback amplification loop involving PGE(2)-induced signaling events linked to beta-catenin/Tcf/Lef-dependent transcription of tumor survival genes including cox-2 itself and survivin. PMID:19244345

  15. Suppressing cyclooxygenase-2 prevents nonalcoholic and inhibits apoptosis of hepatocytes that are involved in the Akt/p53 signal pathway.

    PubMed

    Wu, Jialing; Chen, Chong; Hu, Xi; Cai, Xianbin; Guan, Yinghong; Hu, Hui; Wang, Qinjia; Chen, Xiaofeng; Cai, Bozhi; Jing, Xubin

    2016-01-22

    Cyclooxygenase-2 (COX-2) can exert pro-inflammatory effects in nonalcoholic steatohepatitis (NASH). The aim of this study was to determine if the inhibition of COX-2 attenuates hepatocyte apoptosis in steatohepatitis and to examine the underlying molecular mechanism. Male wild type C57BL6/J mice and COX-2 knock out (COX-2-/-) mice were fed a methionine choline deficient (MCD) diet for 3 weeks. The wild type mice were also treated with celecoxib or a combination of celecoxib and a Akt specific inhibitor, miltefosine (MTF). After that, liver histology, serum alanine aminotransferase (ALT) levels, hepatic triglyceride (TG) levels, hepatocyte apoptosis, phosphorylated Akt (Ser473, pAkt) and p53 protein levels in mice livers were assessed. Celecoxib attenuated the severity of liver steatohepatitis and reduced the number of apoptotic cells, accompanied by increasing the activity of Akt and decreasing expression of p53. On the contrary, MTF can abrogate the effects of celecoxib on anti-apoptosis and anti-steatohepatitis. Moreover, the effects on the COX-2-/- mice that were fed the MCD diet were similar to that for celecoxib. The findings suggested that suppressing COX-2 can improve steatohepatitis by inhibiting hepatocyte apoptosis in mice via regulating the Akt/p53 pathway. Celecoxib treatment may be a favorable treatment option for NASH. PMID:26723251

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

    EPA Science Inventory

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

  17. Radiation Therapy Overcomes Adverse Prognostic Role of Cyclooxygenase-2 Expression on Reed-Sternberg Cells in Early Hodgkin Lymphoma

    SciTech Connect

    Mestre, Francisco; Gutiérrez, Antonio; Rodriguez, Jose; Ramos, Rafael; Garcia, Juan Fernando; Martinez-Serra, Jordi; Casasus, Marta; Nicolau, Cristina; Bento, Leyre; Herraez, Ines; Lopez-Perezagua, Paloma; Daumal, Jaime; Besalduch, Joan

    2015-05-01

    Purpose: To analyze the role of radiation therapy (RT) on the adverse prognostic influence of cyclooxygenase-2 (COX-2) expression on Reed-Sternberg (RS) cells, in the setting of early Hodgkin lymphoma (HL) treated with ABVD (adriamycin, vinblastine, bleomycin, dacarbazine). Methods and Materials: In the present study we retrospectively investigated the prognostic value of COX-2 expression in a large (n=143), uniformly treated early HL population from the Spanish Network of HL using tissue microarrays. Univariate and multivariate analyses were done, including the most recognized clinical variables and the potential role of administration of adjuvant RT. Results: Median age was 31 years; the expression of COX-2 defined a subgroup with significantly worse prognosis. Considering COX-2{sup +} patients, those who received RT had significantly better 5-year progression-free survival (PFS) (80% vs 54% if no RT; P=.008). In contrast, COX-2{sup −} patients only had a modest, nonsignificant benefit from RT in terms of 5-year PFS (90% vs 79%; P=.13). When we compared the outcome of patients receiving RT considering the expression of COX-2 on RS cells, we found a nonsignificant 10% difference in terms of PFS between COX-2{sup +} and COX-2{sup −} patients (P=.09), whereas the difference between the 2 groups was important (25%) in patients not receiving RT (P=.04). Conclusions: Cyclooxygenase-2 RS cell expression is an adverse independent prognostic factor in early HL. Radiation therapy overcomes the worse prognosis associated with COX-2 expression on RS cells, acting in a chemotherapy-independent way. Cyclooxygenase-2 RS cell expression may be useful for determining patient candidates with early HL to receive consolidation with RT.

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

    PubMed Central

    Sundar, Durai; Thorat, Sunil S.

    2014-01-01

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

  19. Localization of cyclooxygenase-2 and prostaglandin E2 receptor EP3 in the rat lumbar spinal cord.

    PubMed

    Beiche, F; Klein, T; Nüsing, R; Neuhuber, W; Goppelt-Struebe, M

    1998-08-14

    Cyclooxygenase-2 (COX-2) is now considered to be the major constitutively expressed COX isozyme in the central nervous system. The present immunocytochemical study details localization of COX-2 immunoreactivity in rat spinal cord along with the expression of prostaglandin E2 receptor subtype EP3. Prominent COX-2 staining was observed in the nuclear envelope of neurons throughout the spinal cord, especially in the superficial dorsal horn laminae and motoneurons of lamina IX, as well as in glial cells of the white matter. Expression of EP3 receptor was strictly confined to afferent terminal areas in the superficial dorsal horns. PMID:9726822

  20. Dual inhibition of cyclooxygenase-2 and soluble epoxide hydrolase synergistically suppresses primary tumor growth and metastasis

    PubMed Central

    Zhang, Guodong; Panigrahy, Dipak; Hwang, Sung Hee; Yang, Jun; Mahakian, Lisa M.; Wettersten, Hiromi I.; Liu, Jun-Yan; Wang, Yanru; Ingham, Elizabeth S.; Tam, Sarah; Kieran, Mark W.; Weiss, Robert H.; Ferrara, Katherine W.; Hammock, Bruce D.

    2014-01-01

    Prostaglandins derived from the cyclooxygenase (COX) pathway and epoxyeicosatrienoic acids (EETs) from the cytochrome P450/soluble epoxide hydrolase (sEH) pathway are important eicosanoids that regulate angiogenesis and tumorigenesis. COX-2 inhibitors, which block the formation of prostaglandins, suppress tumor growth, whereas sEH inhibitors, which increase endogenous EETs, stimulate primary tumor growth and metastasis. However, the functional interactions of these two pathways in cancer are unknown. Using pharmacological inhibitors as probes, we show here that dual inhibition of COX-2 and sEH synergistically inhibits primary tumor growth and metastasis by suppressing tumor angiogenesis. COX-2/sEH dual pharmacological inhibitors also potently suppress primary tumor growth and metastasis by inhibiting tumor angiogenesis via selective inhibition of endothelial cell proliferation. These results demonstrate a critical interaction of these two lipid metabolism pathways on tumorigenesis and suggest dual inhibition of COX-2 and sEH as a potential therapeutic strategy for cancer therapy. PMID:25024195

  1. Non-Selective Evolution of Growing Populations

    PubMed Central

    Jung, Heinrich; Frey, Erwin

    2015-01-01

    Non-selective effects, like genetic drift, are an important factor in modern conceptions of evolution, and have been extensively studied for constant population sizes (Kimura, 1955; Otto and Whitlock, 1997). Here, we consider non-selective evolution in the case of growing populations that are of small size and have varying trait compositions (e.g. after a population bottleneck). We find that, in these conditions, populations never fixate to a trait, but tend to a random limit composition, and that the distribution of compositions “freezes” to a steady state. This final state is crucially influenced by the initial conditions. We obtain these findings from a combined theoretical and experimental approach, using multiple mixed subpopulations of two Pseudomonas putida strains in non-selective growth conditions (Matthijs et al, 2009) as model system. The experimental results for the population dynamics match the theoretical predictions based on the Pólya urn model (Eggenberger and Pólya, 1923) for all analyzed parameter regimes. In summary, we show that exponential growth stops genetic drift. This result contrasts with previous theoretical analyses of non-selective evolution (e.g. genetic drift), which investigated how traits spread and eventually take over populations (fixate) (Kimura, 1955; Otto and Whitlock, 1997). Moreover, our work highlights how deeply growth influences non-selective evolution, and how it plays a key role in maintaining genetic variability. Consequently, it is of particular importance in life-cycles models (Melbinger et al, 2010; Cremer et al, 2011; Cremer et al, 2012) of periodically shrinking and expanding populations. PMID:26274606

  2. Human cyclooxygenase-2 is a sequence homodimer that functions as a conformational heterodimer.

    PubMed

    Dong, Liang; Vecchio, Alex J; Sharma, Narayan P; Jurban, Brice J; Malkowski, Michael G; Smith, William L

    2011-05-27

    Prostaglandin endoperoxide H synthases 1 and 2, also known as cyclooxygenases (COXs) 1 and 2, convert arachidonic acid (AA) to prostaglandin endoperoxide H(2). Prostaglandin endoperoxide H synthases are targets of nonspecific nonsteroidal anti-inflammatory drugs and COX-2-specific inhibitors called coxibs. PGHS-2 is a sequence homodimer. Each monomer has a peroxidase and a COX active site. We find that human PGHS-2 functions as a conformational heterodimer having a catalytic monomer (E(cat)) and an allosteric monomer (E(allo)). Heme binds tightly only to the peroxidase site of E(cat), whereas substrates, as well as certain inhibitors (e.g. celecoxib), bind the COX site of E(cat). E(cat) is regulated by E(allo) in a manner dependent on what ligand is bound to E(allo). Substrate and nonsubstrate fatty acids (FAs) and some COX inhibitors (e.g. naproxen) preferentially bind to the COX site of E(allo). AA can bind to E(cat) and E(allo), but the affinity of AA for E(allo) is 25 times that for E(cat). Palmitic acid, an efficacious stimulator of human PGHS-2, binds only E(allo) in palmitic acid/murine PGHS-2 co-crystals. Nonsubstrate FAs can potentiate or attenuate actions of COX inhibitors depending on the FA and whether the inhibitor binds E(cat) or E(allo). Our studies suggest that the concentration and composition of the free FA pool in the environment in which PGHS-2 functions in cells, the FA tone, is a key factor regulating PGHS-2 activity and its responses to COX inhibitors. We suggest that differences in FA tone occurring with different diets will likely affect both base-line prostanoid synthesis and responses to COX inhibitors. PMID:21467029

  3. Targeting angiogenic pathway for chemoprevention of experimental colon cancer using C-phycocyanin as cyclooxygenase-2 inhibitor.

    PubMed

    Saini, Manpreet Kaur; Sanyal, Sankar Nath

    2014-06-01

    An angiogenic pathway was studied that involved stromal tissue degradation with matrix metalloproteinases (MMPs), vesicular endothelial growth factor-A (VEGF-A), and hypoxia inducible factor-1α (HIF-1α) mediated growth regulation in a complex interaction with chemokines, such as monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1β (MIP-1β). Gene and protein expression was studied with real-time PCR, Western immunoblot, and immunofluorescence. Morphological and histopathological analysis of tumor was done, as also the activity of MMPs and HIF-1α by gelatin zymography and ELISA. Binding interactions of proteins were studied by molecular docking. Piroxicam, a traditional NSAID and C-phycocyanin, a biliprotein from Spirulina platensis, were utilized in the chemoprevention of DMH-induced rat colon cancer. A significant number of tumors was evident in DMH treated animals, while with piroxicam and C-phycocyanin, the number and size of tumors/lesions were reduced. Colonic tissues showed severe dysplasia, tubular adenoma, and adenocarcinoma from DMH, with invasive features along with signet ring cell carcinoma. No occurrence of carcinoma was detected in either of the drug treatments or in a combination regimen. An elevated VEGF-A, MMP-2, and MMP-9 level was observed, which is required for metastasis and invasion into surrounding tissues. Drugs induced chemoprevention by down-regulating these proteins. Piroxicam docked in VEGF-A binding site of VEGF-A receptors i.e., VEGFR1 and VEGFR2, while phycocyanobilin (a chromophore of C-phycocyanin) docked with VEGFR1 alone. HIF-1α is up-regulated which is associated with increased oxygen demand and angiogenesis. MCP-1 and MIP-1β expression was also found altered in DMH and regulated by the drugs. Anti-angiogenic role of piroxicam and C-phycocyanin is well demonstrated. PMID:24861078

  4. The preferential nNOS inhibitor 7-nitroindazole and the non-selective one N(G)-nitro-L-arginine methyl ester administered alone or jointly with L-DOPA differentially affect motor behavior and monoamine metabolism in sham-operated and 6-OHDA-lesioned rats.

    PubMed

    Czarnecka, Anna; Konieczny, Jolanta; Lenda, Tomasz; Lorenc-Koci, Elżbieta

    2015-11-01

    Reciprocal interactions between nitrergic and dopaminergic systems play a key role in the control of motor behavior. In the present study, we performed a comparative analysis of motor behavior (locomotor activity, catalepsy, rotational behavior) and monoamine metabolism in the striatum and substantia nigra of unilaterally sham-operated and 6-OHDA-lesioned rats treated with the preferential neuronal nitric oxide synthase (nNOS) inhibitor 7-nitroindazole (7-NI) or the non-selective one N(G)-nitro-L-arginine methyl ester (L-NAME), alone or in combination with L-DOPA. Each NOS inhibitor given alone (50mg/kg) induced a distinct catalepsy 30 min after injection but only 7-NI impaired spontaneous locomotion after 10 min. In 6-OHDA-lesioned rats, chronic L-DOPA (25mg/kg) induced 2.5-h long contralateral rotations. 7-NI (30 and 50mg/kg) markedly reduced the intensity of L-DOPA-induced contralateral rotations while extending their duration until 4.5h whereas L-NAME (50 and 100mg/kg) only tended to attenuate their intensity without affecting the duration. 7-NI but not L-NAME significantly increased endogenous tissue DA levels in the nigrostriatal system of both sham-operated and 6-OHDA-lesioned rats. In L-DOPA-treated group, 7-NI significantly enhanced the L-DOPA-derived tissue DA content in this system and decreased the level of the intracellular DA metabolite DOPAC produced by monoamine oxidase (MAO). In contrast to 7-NI, L-NAME decreased markedly DA content and did not affect DOPAC level in the ipsilateral striatum. It means that the differences in 7-NI and L-NAME-mediated modulation of L-DOPA-induced behavioral and biochemical effects resulted not only from the inhibition of NOS activity but also from differences in their ability to inhibit MAO. PMID:26319690

  5. Arachidonoyl-ethanolamide activates endoplasmic reticulum stress-apoptosis in tumorigenic keratinocytes: Role of cyclooxygenase-2 and novel J-series prostamides.

    PubMed

    Soliman, Eman; Henderson, Kate L; Danell, Allison S; Van Dross, Rukiyah

    2016-02-01

    Non-melanoma skin cancer and other epithelial tumors overexpress cyclooxygenase-2 (COX-2), differentiating them from normal cells. COX-2 metabolizes arachidonic acid to prostaglandins including, the J-series prostaglandins, which induce apoptosis by mechanisms including endoplasmic reticulum (ER) stress. Arachidonoyl-ethanolamide (AEA) is a cannabinoid that causes apoptosis in diverse tumor types. Previous studies from our group demonstrated that AEA was metabolized by COX-2 to J-series prostaglandins. Thus, the current study examines the role of COX-2, J-series prostaglandins, and ER stress in AEA-induced apoptosis. In tumorigenic keratinocytes that overexpress COX-2, AEA activated the PKR-like ER kinase (PERK), inositol requiring kinase-1 (IRE1), and activating transcription factor-6 (ATF6) ER stress pathways and the ER stress apoptosis-associated proteins, C/EBP homologous protein-10 (CHOP10), caspase-12, and caspase-3. Using an ER stress inhibitor, it was determined that ER stress was required for AEA-induced apoptosis. To evaluate the role of COX-2 in ER stress-apoptosis, HaCaT keratinocytes with low endogenous COX-2 expression were transfected with COX-2 cDNA or an empty vector and AEA-induced ER stress-apoptosis occurred only in the presence of COX-2. Moreover, LC-MS analysis showed that the novel prostaglandins, 15-deoxyΔ(12,14) PGJ2 -EA and Δ(12) PGJ2 /PGJ2-EA, were synthesized from AEA. These findings suggest that AEA will be selectively toxic in tumor cells that overexpress COX-2 due to the metabolism of AEA by COX-2 to J-series prostaglandin-ethanolamides (prostamides). Hence, AEA may be an ideal topical agent for the elimination of malignancies that overexpress COX-2. PMID:25557612

  6. Persistent cyclooxygenase-2 inhibition downregulates NF-{kappa}B, resulting in chronic intestinal inflammation in the min/+ mouse model of colon tumorigenesis.

    PubMed

    Carothers, Adelaide M; Davids, Jennifer S; Damas, Beatrice C; Bertagnolli, Monica M

    2010-06-01

    Cyclooxygenase-2 (COX-2) inhibition prevents adenoma formation in humans and mouse models of colon cancer. The selective COX-2 inhibitor celecoxib reduces COX-2 and prostaglandin E(2) (PGE(2)) expression and adenomas in the intestine of Min/+ mice after treatment for several weeks, but prolonged treatment increases PGE(2) production, resulting in drug-resistant tumor formation and transforming growth factor beta (TGFbeta)-dependent intestinal fibrosis. In this study, we examined pathways that regulate COX-2 expression and suppress chronic intestinal inflammation. We show that NF-kappaB signaling was inhibited in the ileum of Min/+ mice receiving long-term treatment with celecoxib. This effect was associated with inhibition of TGFbeta-associated kinase-1 and IkappaB kinase alpha/beta activities and reduced expression of the Toll-like receptor (TLR) 2 and TLR4 that enhance colonic barrier function. Additionally, we observed reduced activities of protein kinases c-Jun NH(2)-terminal kinase 1 and protein kinase A and transcription factor cyclic AMP-responsive element binding protein, regulators of COX-2 expression, which cross-talk with NF-kappaB. In ileum subjected to long-term celecoxib treatment, we noted relatively higher expression of COX-2, vascular endothelial growth factor, and interleukin-1beta in Paneth cells, whereas NF-kappaB and COX-2 were more strongly expressed by an expanded population of stromal myofibroblasts. Our findings argue that celecoxib resistance is an acquired adaptation to changes in the crypt microenvironment that is associated with chronic intestinal inflammation and impaired acute wound-healing responsiveness. PMID:20484034

  7. Estrogen-Dependent Prognostic Significance of Cyclooxygenase-2 Expression in Early-Stage Invasive Breast Cancers Treated With Breast-Conserving Surgery and Radiation

    SciTech Connect

    Haffty, Bruce G. Yang Qifeng; Moran, Meena S.; Tan, Antoinette R.; Reiss, Michael

    2008-07-15

    Purpose: To evaluate the prognostic significance of cyclooxygenase-2 (COX-2) in breast cancer patients treated with conservative surgery and radiation therapy (CS+RT). Methods and Materials: Between 1975 and 2003, we retrieved specimens from 504 breast cancer patients treated with CS+RT. The specimens were constructed into tissue microarrays processed and stained for estrogen receptor (ER), progesterone receptor, Her2/neu, and COX-2. Each core was scored as positive or negative. All data including demographics, clinical, pathologic, staging, and outcome variables were entered into a computerized database. Results: Expression of COX-2 was positive in 58% of cases and correlated with younger age (p = 0.01) and larger tumor size (p 0.001). Expression of COX-2 was predictive of local relapse (relative risk[RR], 3.248; 95% confidence interval [CI], 1.340-7.871; p = 0.0091), distant metastasis (RR, 2.21; 95% CI, 1.259-3.896; p = 0.0058), and decreased survival (RR, 2.321; 95% CI, 1.324-4.071; p = 0.0033). Among ER-positive patients, COX-2 expression was predictive of worse local control (85% vs. 93%, p = 0.04), distant metastasis (75% vs. 95%, p = 0.002) and worse survival (65% vs. 94%, p = 0.002). Among ER-negative tumors COX-2 expression was not significantly correlated with local control (87 vs. 95%, p = 0.12), distant metastasis (73% vs. 78%, p = 0.39), or survival (77% vs. 87%, p 0.15). Conclusions: In breast cancer patients treated with CS+RT, COX-2 expression is associated with younger age, larger tumor size, worse local control, distant metastasis, and worse overall survival. The significance is limited to hormone receptor-positive tumors, consistent with the known effect of COX-2/PGE2 on aromatase activity. Use of COX-2 inhibitors in estrogen-dependent breast cancers warrants further investigation.

  8. Cigarette smoke condensate activates nuclear transcription factor-kappaB through phosphorylation and degradation of IkappaB(alpha): correlation with induction of cyclooxygenase-2.

    PubMed

    Anto, Ruby John; Mukhopadhyay, Asok; Shishodia, Shishir; Gairola, C Gary; Aggarwal, Bharat B

    2002-09-01

    Cigarette smoke (CS) contains several carcinogens known to initiate and promote tumorigenesis and metastasis. Because various genes that mediate carcinogenesis and tumorigenesis are regulated by nuclear factor-kappaB (NF-kappaB), we postulated that the effects of CS must be mediated through activation of this transcription factor. Therefore, in the present report we investigated whether cigarette smoke condensate (CSC) activates NF-kappaB, and whether the pathway employed for activation is similar to that of TNF, one of the potent activators of NF-kappaB. Our results show that the treatment of human histiocytic lymphoma U-937 cells with CSC activated NF-kappaB in a dose- and time-dependent manner. The kinetics of NF-kappaB activation by CSC was comparable with that of TNF. CSC-induced NF-kappaB activation was not cell type-specific, as it also activated NF-kappaB in T cells (Jurkat), lung cells (H1299), and head and neck squamous cell lines (1483 and 14B). Activation of NF-kappaB by CSC correlated with time-dependent degradation of IkappaB(alpha), an inhibitor of NF-kappaB. Further studies revealed that CSC induced phosphorylation of the serine residue at position 32 in IkappaB(alpha). In vitro immunocomplex kinase assays showed that CSC activated IkappaB(alpha) kinase (IKK). The suppression of CSC-activated NF-kappaB-dependent reporter gene expression by dominant negative form of IkappaB(alpha), TRAF2, NIK and IKK suggests a similarity to the TNF-induced pathway for NF-kappaB. CSC also induced the expression of cyclooxygenase-2, an NF-kappaB regulated gene product. Overall, our results indicate that through phosphorylation and degradation of IkappaB(alpha), CSC can activate NF-kappaB in a wide a variety of cells, and this may play a role in CS-induced carcinogenesis. PMID:12189195

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

    PubMed

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

    2009-01-01

    : The beneficial actions of non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with inhibition of cyclooxygenase-2 (COX-2), whereas some of their adverse effects are associated mainly with inhibition of COX-1. Selective COX-2 inhibitors reduce the risk of gastrointestinal adverse events, but increase the risk of thromboembolic events pointing to importance of optimal COX-1/COX-2 inhibition in drug safety. We compared the effects of acetylsalicylic acid, ibuprofen, nabumetone and nimesulide on COX-1 and COX-2 pathways in healthy volunteers in an ex vivo set-up using single oral doses commonly used to treat acute pain. In a randomized, double-blind four-phase cross-over study, 15 healthy volunteers were given orally a single dose of either acetylsalicylic acid 500 mg, ibuprofen 400 mg, nabumetone 1 g or nimesulide 100 mg. Blood samples were drawn before and 1, 3, 6, 24 and 48 hr after the drug for the assessment of COX-1 and COX-2 activity. COX-1 activity was measured as thromboxane(2) production during blood clotting and COX-2 activity as endotoxin-induced prostaglandin E(2) synthesis in blood leucocytes. The data show that after a single oral dose these four NSAIDs have different profiles of action on COX-1 and COX-2. As expected, acetylsalicylic acid appeared to be COX-1-selective and ibuprofen effectively inhibited both COX-1 and COX-2. Nabumetone showed only a slight inhibitory effect on COX-1 and COX-2. Nimesulide caused almost complete suppression of COX-2 activity and a partial reduction of COX-1 activity. This confirms the relative COX-2 selectivity of nimesulide. PMID:19152549

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

    SciTech Connect

    Wu Weidong Silbajoris, Robert A.; Cao Dongsun; Bromberg, Philip A.; Zhang Qiao; Peden, David B.; Samet, James M.

    2008-09-01

    Exposure to zinc-laden particulate matter in ambient and occupational settings has been associated with proinflammatory responses in the lung. Cyclooxygenase 2-derived eicosanoids are important modulators of airway inflammation. In this study, we characterized the transcriptional and posttranscriptional events that regulate COX-2 expression in a human bronchial epithelial cell line BEAS-2B exposed to Zn{sup 2+}. Zn{sup 2+} exposure resulted in pronounced increases in COX-2 mRNA and protein expression, which were prevented by pretreatment with the transcription inhibitor actinomycin D, implying the involvement of transcriptional regulation. This was supported by the observation of increased COX-2 promoter activity in Zn{sup 2+}-treated BEAS-2B cells. Mutation of the cAMP response element (CRE), but not the {kappa}B-binding sites in the COX-2 promoter markedly reduced COX-2 promoter activity induced by Zn{sup 2+}. Inhibition of NF{kappa}B activation did not block Zn{sup 2+}-induced COX-2 expression. Measurement of mRNA stability demonstrated that Zn{sup 2+} exposure impaired the degradation of COX-2 mRNA in BEAS-2B cells. This message stabilization effect of Zn{sup 2+} exposure was shown to be dependent on the integrity of the 3'-untranslated region found in the COX-2 transcript. Taken together, these data demonstrate that the CRE and mRNA stability regulates COX-2 expression induced in BEAS-2B cells exposed to extracellular Zn{sup 2+}.

  11. Cyclooxygenase-2 is widely expressed in atherosclerotic lesions affecting native and transplanted human coronary arteries and colocalizes with inducible nitric oxide synthase and nitrotyrosine particularly in macrophages.

    PubMed

    Baker, C S; Hall, R J; Evans, T J; Pomerance, A; Maclouf, J; Creminon, C; Yacoub, M H; Polak, J M

    1999-03-01

    Inflammation appears to have a major role in the development of atherosclerotic lesions affecting native and transplanted coronary arteries. The subsequent risk of plaque rupture and acute ischemic events correlates with the degree of inflammation and may be modified by aspirin, an anti-inflammatory cyclooxygenase inhibitor. Cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNOS) are involved in the inflammatory response via the rapid and exaggerated production of prostanoids and nitric oxide, both of which may have proatherosclerotic effects. These effects may be mediated by the formation of peroxynitrite in the case of nitric oxide and involve "cross talk" between the two enzyme systems. This study aimed to investigate native and transplant atherosclerosis for the presence and distribution of Cox-2 and iNOS. Immunocytochemical studies were performed on atherosclerotic lesions from patients with native (n=12) and transplant (n=5) coronary disease by using antibodies to Cox-2, iNOS, and nitrotyrosine (an indicator of peroxynitrite production). Control tissue was obtained from unused donor hearts and at the time of autopsy. Cox-2 and iNOS colocalized predominantly in macrophages/foam cells in both types of atherosclerosis. Cox-2 expression was also detected in medial smooth muscle cells and endothelial cells, including those of the vasa vasorum. Nitrotyrosine was found in the same distribution as that of iNOS and was colocalized with Cox-2 in macrophages. Cox-2 and iNOS are coexpressed in native and transplant atherosclerosis, possibly allowing for interaction between the enzymes and suggesting an alternative mechanism for the benefits of aspirin via inhibition of Cox-2 activity. PMID:10073969

  12. Mitochondrial localization of cyclooxygenase-2 and calcium-independent phospholipase A{sub 2} in human cancer cells: Implication in apoptosis resistance

    SciTech Connect

    Liou, J.-Y.; Aleksic, Nena; Chen, S.-F.; Han, T.-J.; Shyue, Song-Kun . E-mail: skshyue@ibms.sinica.edu.tw; Wu, Kenneth K. . E-mail: Kenneth.K.Wu@uth.tmc.edu

    2005-05-15

    Cyclooxygenase-2 (COX-2) is inducible by myriad stimuli. The inducible COX-2 in primary cultured human cells has been reported to localize to nuclear envelope, endoplasmic reticulum, nucleus and caveolae. As COX-2 plays an important role in tumor growth, we were interested in its subcellular location in cancer cells. We examined COX-2 localization in several cancer cell lines by confocal microscopy. A majority of COX-2 was colocalized with heat shock protein 60, a mitochondrial protein, in colon cancer (HT-29, HCT-15 and DLD-1), breast cancer (MCF7), hepatocellular cancer (HepG2) and lung cancer cells (A549) with a similar distribution pattern. By contrast, COX-2 was not localized to mitochondria in human foreskin fibroblasts or endothelial cells. Immunoblot analysis of COX-2 in mitochondrial and cytosolic fractions confirmed localization of COX-2 to mitochondria in HT-29 and DLD-1 cells but not in fibroblasts. Calcium-independent phospholipase A2 was colocalized with heat shock protein 60 to mitochondria not only in cancer cells (HT-29 and DLD-1) but also in fibroblasts. HT-29 which expressed more abundant mitochondrial COX-2 than DLD-1 was highly resistant to arachidonic acid and H{sub 2}O{sub 2}-induced apoptosis whereas DLD-1 was less resistant and human fibroblasts were highly susceptible. Treatment of HT-29 cells with sulindac or SC-236, a selective COX-2 inhibitor, resulted in loss of resistance to apoptosis. These results suggest that mitochondrial COX-2 in cancer cells confer resistance to apoptosis by reducing the proapoptotic arachidonic acid.

  13. Role of Cyclooxygenase-2 in Relation to Nitric Oxide and Endothelin-1 on Pathogenesis of Cerebral Vasospasm After Subarachnoid Hemorrhage in Rabbit.

    PubMed

    Munakata, Akira; Naraoka, Masato; Katagai, Takeshi; Shimamura, Norihito; Ohkuma, Hiroki

    2016-06-01

    Endothelial dysfunctions that include decreased nitric oxide (NO) bioactivity and increased endothelin-1 (ET-1) bioactivity have been considered to be involved in the pathogenesis of cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage (SAH). Recent cardiovascular studies have revealed that cyclooxygenase-2 (COX-2) is involved in a disturbance in cross-talk between NO and ET-1. COX-2 expression was detected in the endothelial cells of a spastic artery after experimental SAH; however, the pathophysiological significance of COX-2 in relation to CVS remains unclear. The aim of this study was to investigate the role of COX-2 in relation to NO and ET-1 in the pathogenesis of CVS by using the COX-2 selective inhibitor, celecoxib. In the SAH group, SAH was simulated using the double-hemorrhage rabbit model. In the celecoxib group, SAH was simulated and celecoxib was administered. The basilar artery was extracted on day 5 and examined. The cross-section area of the basilar artery in the celecoxib group was significantly larger than in the SAH group. An increased expression of COX-2, ET-1, and ETA receptor (ETAR), and a decreased expression of endothelial NO synthase (eNOS) were seen in the SAH group. In the celecoxib group compared to the SAH group, expression of COX-2, ET-1, and ETAR were statistically significantly decreased, and eNOS expression was significantly increased. COX-2 might be involved in the pathogenesis of CVS due to up-regulation of ET-1 and ETAR and down-regulation of eNOS, and celecoxib may potentially serve as an agent in the prevention of CVS after SAH. PMID:27044361

  14. Involvement of cyclooxygenase-2 in carbachol-induced positive inotropic response in mouse isolated left atrium.

    PubMed

    Hara, Yukio; Ike, Asako; Tanida, Riyo; Okada, Muneyoshi; Yamawaki, Hideyuki

    2009-12-01

    The mouse heart is expected to have characteristic contractile properties. However, basic information on the function of the mouse heart has not been accumulated sufficiently. In this study, the involvement of cyclooxygenase (COX)-2 in carbachol (CCh)-induced inotropic response was investigated in mouse isolated left atrium. Influences of CCh and their mechanisms of action on developed tension elicited by electrical stimulation were examined pharmacologically. The presence of COX-2 in atrium was examined by Western blotting and immunohistochemical analysis. CCh (3 microM for 15 min) produced a biphasic inotropic response: a transient decrease in contractile force followed by a late increase. Atropine suppressed the biphasic inotropic response to CCh. A muscarinic M(3) receptor antagonist, 4-diphenyl-acetoxy-N-methlpiperidine, inhibited the late positive inotropic action. Blockade of prostaglandin (PG) E(2) or F(2alpha) receptor by 6-isopropoxy-9-oxoxanthene-2-carboxylic acid (AH6809) or 9alpha, 15R-dihydroxy-11beta-fluoro-15-(2,3-dihydro-1H-inden-2-yl)-16,17,18,19,20-pentanor-prosta 5Z, 13E-dien-1-oic acid (AL8810), respectively, significantly suppressed the positive inotropic response to CCh. A nonselective COX inhibitor, indomethacin, and a selective COX-2 inhibitor, N-[2-(cyclohexyloxy)-4-nitrophenyl]-methanesulfonamide (NS-398) inhibited the positive response. A COX-1 inhibitor, valeroyl salicylate, did not affect the positive response. The positive response was almost completely abolished in the endocardial endothelium-deprived atria. Existence of COX-2 in endocardial endothelium was confirmed by Western blotting and immunohistochemical analysis. The present study indicated that the CCh-induced positive inotropic response was mediated by PGs, possibly PGE(2) and PGF(2alpha), released in part from endocardial endothelium. Furthermore, for the first time, we demonstrated that the production of PGs depended in part on COX-2 in endocardial endothelium through the

  15. Requirement of cyclooxygenase-2 expression and prostaglandins for human prostate cancer cell invasion.

    PubMed

    Nithipatikom, Kasem; Isbell, Marilyn A; Lindholm, Paul F; Kajdacsy-Balla, Andre; Kaul, Sushma; Campell, William B

    2002-01-01

    The PC-3 Low Invasive cells and the PC-3 High Invasive cells were used to investigate the correlation of the COX-2 expression and its arachidonic acid metabolites, prostaglandins, with their invasiveness through Matrigel using a Boyden chamber assay. The COX-2 expression in PC-3 High Invasive cells was approximately 3-fold higher than in PC-3 Low Invasive cells while the COX-1 expression was similar in both cell sublines. When incubated with arachidonic acid, PGE2 was the major prostaglandin produced by these cells. PC-3 High Invasive cells produced PGE2 approximately 2.5-fold higher than PC-3 Low Invasive cells. PGD2 was the second most abundant prostaglandin produced by these cells. Both indomethacin (a nonspecific COX inhibitor) and NS-398 (a specific COX-2 inhibitor) inhibited the production of prostaglandins and the cell invasion. PGE2 alone did not induce the cell invasion of PC-3 Low Invasive cells. However, PGE2 reversed the inhibition of cell invasion by NS-398 and enhanced the cell invasion of the PC-3 High Invasive cells. In contrast, PGD2 slightly inhibited the cell invasion. These results suggest that in the PC-3 Low Invasive cells, COX-2-derived PGE2 may not be sufficient to induce cell invasion while in the PC-3 High Invasive cells, PGE2 may be sufficient to act as an enhancer for the cell invasion. Further, PGD2 may represent a weak inhibitor and counteracts the effect of PGE2 in the cell invasion. PMID:12498388

  16. Cyclic stretch induces cyclooxygenase-2 gene expression in vascular endothelial cells via activation of nuclear factor kappa-{beta}

    SciTech Connect

    Zhao, Haige; Hiroi, Toyoko; Hansen, Baranda S.; Rade, Jeffrey J.

    2009-11-27

    Vascular endothelial cells respond to biomechanical forces, such as cyclic stretch and shear stress, by altering gene expression. Since endothelial-derived prostanoids, such as prostacyclin and thromboxane A{sub 2}, are key mediators of endothelial function, we investigated the effects of cyclic stretch on the expression of genes in human umbilical vein endothelial cells controlling prostanoid synthesis: cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), prostacyclin synthase (PGIS) and thromboxane A{sub 2} synthase (TXAS). COX-2 and TXAS mRNAs were upregulated by cyclic stretch for 24 h. In contrast, PGIS mRNA was decreased and stretch had no effect on COX-1 mRNA expression. We further show that stretch-induced upregulation of COX-2 is mediated by activation of the NF-{kappa}{beta} signaling pathway.

  17. Clinical significance of cyclooxygenase-2 expression in extranodal natural killer (NK)/T-cell lymphoma, nasal type

    SciTech Connect

    Shim, Su Jung; Yang, Woo-Ick; Shin, Eunah; Koom, Woong Sub; Kim, Yong Bae; Cho, Jae Ho; Suh, Chang Ok; Kim, Joo Hang; Kim, Gwi Eon . E-mail: gekim@yumc.yonsei.ac.kr

    2007-01-01

    Purpose: To determine whether there are any differences in therapeutic response, patterns of systemic recurrence, and prognosis of patients with extranodal natural killer (NK)/T-cell lymphoma, nasal type, by the cyclooxygenase-2 (COX-2) expression. Patients and Methods: Thirty-four patients with Ann Arbor Stage I and II extranodal NK/T-cell lymphoma who underwent chemotherapy or radiotherapy, or both, were retrospectively reviewed. These patients were divided into two groups according to their immunohistochemical staining for COX-2 expressions: a COX-2-negative group (n = 10 patients) and a COX-2-positive group (n = 24 patients). The treatment response, patterns of treatment failure, and survival data for the patients were compared between the COX-2-positive and negative groups. Results: There was no significant difference in the clinical profiles between the COX-2-negative and COX-2-positive groups. All patients (100%) in the COX-2-negative group achieved complete response after initial treatment, whereas only 14 patients (58%) in the COX-2-positive group achieved complete response (p = 0.03). Compared with the patients in the COX-2-negative group, those in the COX-2-positive group had a significantly lower 2-year systemic recurrence-free survival rate (100% for the COX-2-negative group vs. 54% for the COX-2-positive group) (p = 0.02) and a decreased 5-year overall survival rate (70% for the COX-2-negative group vs. 32% for the COX-2-positive group) (p = 0.06). Conclusion: Cyclooxygenase-2 expression can serve as a predictive factor for poor treatment response, higher systemic recurrence, and unfavorable prognosis in patients with extranodal NK/T-cell lymphoma, nasal type.

  18. Lack of association between the cyclooxygenase 2 -765G>C polymorphism and prostate cancer risk: a meta-analysis.

    PubMed

    Feng, Y-Q; Li, Y U; Xiao, W-D; Wang, G-X; Li, Y O

    2015-01-01

    The aim of this study was to investigate the association between the cyclooxygenase 2 (COX2) -765G>C (rs20417) polymorphism and prostate cancer (PC) risk using meta-analysis. A systematic literature search was performed using the PubMed, Embase, Cochrane Library, and Google Scholar databases by using the terms "cyclooxygenase-2/COX-2/PTGs2", "polymorphism" or "variation", and "prostate" and "cancer" or "carcinoma" to identify relevant articles up to June 14, 2014. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were assessed for PC risk associated with COX2 -765G>C polymorphism using fixed- and random-effect models. We identified a total of nine publications, including 5952 cases and 5078 controls, to investigate the effect of COX2 -765G>C on PC risk, and found no significant association in any genetic model tested (CC vs GG: OR = 0.993, 95%CI = 0.923-1.068; GC+CC vs GG: OR = 1.041, 95%CI = 0.931-1.103; CC vs GC+GG: OR = 0.858, 95%CI = 0.689-1.067; CC vs GG: OR = 0.871, 95%CI = 0.689-1.086; GC vs GG: OR = 1.032, 95%CI = 0.945-1.127). Power analysis and tests for publication bias ensured the reliability of our results. This meta-analysis suggested that the functional COX2 -765G>C polymorphism, located in the COX2 gene promoter, is unlikely to be associated with PC risk. However, additional larger, well-designed studies are still required to reach a conclusive result on this issue. PMID:26535654

  19. Adverse Effects of Oral Nonselective and cyclooxygenase-2-Selective NSAIDs on Hospitalization for Acute Kidney Injury

    PubMed Central

    Chou, Chia-I.; Shih, Chia-Jen; Chen, Yung-Tai; Ou, Shuo-Ming; Yang, Chih-Yu; Kuo, Shu-Chen; Chu, Dachen

    2016-01-01

    Abstract To investigate the association between the use of nonselective or cyclooxygenase (COX)-2-selective nonsteroidal antiinflammatory drugs (NSAIDs) and risk of acute kidney injury (AKI) in a general Asian population. We conducted an observational, nationwide, nested case–control cohort study using Taiwan's National Health Insurance Research Database between 2010 and 2012. AKI cases were defined as hospitalization with a principle diagnosis of AKI. Each case was matched to 4 randomly selected controls based on age, sex, and the month and year of cohort entry. Odds ratios (ORs) were used to demonstrate the association between hospitalization for AKI and current, recent, or past use of an oral NSAID. During the study period, we identified 6199 patients with AKI and 24,796 matched controls. Overall, current users (adjusted OR 2.73, 95% confidence interval [CI] 2.28–3.28) and recent users (adjusted OR 1.17, 95% CI 1.01–1.35) were associated with increased risk of hospitalization for AKI. The risk was also similar for nonselective NSAIDs. However, neither current nor recent use of COX-2 inhibitors was significantly associated with AKI events. Our study supported that the initiation of nonselective NSAIDs rather than COX-2 inhibitors is associated with an increased risk of AKI requiring hospitalization. Future randomized trials are needed to elucidate these findings. PMID:26945352

  20. Statins Modulate Cyclooxygenase-2 and Microsomal Prostaglandin E Synthase-1 in Human Hepatic Myofibroblasts.

    PubMed

    Mouawad, Charbel A; Mrad, May F; El-Achkar, Ghewa A; Abdul-Sater, Ali; Nemer, Georges M; Creminon, Christophe; Lotersztajn, Sophie; Habib, Aïda

    2016-05-01

    Statins have been shown to exert anti-inflammatory and anti-fibrogenic properties in the liver. In the present study, we explored the mechanisms underlying anti-fibrogenic effects of statins in isolated hepatic myofibroblasts and focused on cyclooxyegnase-2, a major anti-proliferative pathway in these cells. We show that simvastatin and fluvastatin inhibit thymidine incorporation in hMF in a dose-dependent manner. Pretreatment of cells with NS398, a COX-2 inhibitor, partially blunted this effect. cAMP levels, essential to the inhibition of hMF proliferation, were increased by statins and inhibited by non-steroidal anti-inflammatory drugs. Since statins modify prenylation of some important proteins in gene expression, we investigated the targets involved using selective inhibitors of prenyltransferases. Inhibition of geranylgeranylation resulted in the induction of COX-2 and mPGES-1. Using gel retardation assays, we further demonstrated that statins potentially activated the NFκB and CRE/E-box binding for COX-2 promoter and the binding of GC-rich regions and GATA for mPGES-1. Together these data demonstrate that statin limit hepatic myofibroblasts proliferation via a COX-2 and mPGES-1 dependent pathway. These data suggest that statin-dependent increase of prostaglandin in hMF contributes to its anti-fibrogenic effect. J. Cell. Biochem. 117: 1176-1186, 2016. © 2015 Wiley Periodicals, Inc. PMID:26477987

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

    PubMed

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

    2008-09-01

    In the present study it was revealed that cannabidiolic acid (CBDA) selectively inhibited cyclooxygenase (COX)-2 activity with an IC(50) value (50% inhibition concentration) around 2 microM, having 9-fold higher selectivity than COX-1 inhibition. In contrast, Delta(9)-tetrahydrocannabinolic acid (Delta(9)-THCA) was a much less potent inhibitor of COX-2 (IC(50) > 100 microM). Nonsteroidal anti-inflammatory drugs containing a carboxyl group in their chemical structures such as salicylic acid are known to inhibit nonselectively both COX-1 and COX-2. CBDA and Delta(9)-THCA have a salicylic acid moiety in their structures. Thus, the structural requirements for the CBDA-mediated COX-2 inhibition were next studied. There is a structural difference between CBDA and Delta(9)-THCA; phenolic hydroxyl groups of CBDA are freed from the ring formation with the terpene moiety, although Delta(9)-THCA has dibenzopyran ring structure. It was assumed that the whole structure of CBDA is important for COX-2 selective inhibition because beta-resorcylic acid itself did not inhibit COX-2 activity. Methylation of the carboxylic acid moiety of CBDA led to disappearance of COX-2 selectivity. Thus, it was suggested that the carboxylic acid moiety in CBDA is a key determinant for the inhibition. Furthermore, the crude extract of cannabis containing mainly CBDA was shown to have a selective inhibitory effect on COX-2. Taken together, these lines of evidence in this study suggest that naturally occurring CBDA in cannabis is a selective inhibitor for COX-2. PMID:18556441

  2. Trifluoromethyl Fluorocoxib A Detects Cyclooxygenase-2 Expression in Inflammatory Tissues and Human Tumor Xenografts

    PubMed Central

    2014-01-01

    Fluorocoxib A is an effective COX-2-targeted optical imaging agent, used for in vivo detection of inflammatory tissues and premalignant and malignant tumors that express elevated levels of COX-2 (Uddin et al. Cancer Res. 2010, 70, 3618–3627). In an effort to discover novel optical probes for COX-2, a trifluoromethyl analogue of fluorocoxib A (CF3-fluorocoxib A) was synthesized and evaluated for its ability to inhibit COX-2 in vitro purified enzyme and human cancer cell lines. Kinetic analysis revealed that CF3-fluorocoxib A is a slow, tight binding inhibitor of COX-2 that exhibits low nanomolar inhibitory potency. While CF3-fluorocoxib A and fluorocoxib A are similar in structure, CF3-fluorocoxib A shows improved potency in inhibition of wtCOX-2 and with a series of site-directed COX-2 mutants. After intraperitoneal injection, selective uptake of CF3-fluorocoxib A is detected in inflamed mouse paws compared to noninflamed contralateral paws by optical imaging, and uptake is blocked by pretreatment with the COX-2 inhibitor, celecoxib. Selective uptake is also detected in the COX-2-positive human tumor xenografts (1483 HNSCC) as compared with the COX-2-negative tumor xenografts (HCT116) in an in vivo nude mouse tumor model. These in vitro and in vivo studies suggest that binding to COX-2 is the major determinant of uptake of CF3-fluorocoxib A into the inflamed tissues and tumor xenografts. Thus, this new COX-2-targeted imaging probe should find utility in the detection and evaluation of COX-2 status in naturally occurring malignancies. PMID:24900856

  3. Group X Secretory Phospholipase A2 Regulates Insulin Secretion through a Cyclooxygenase-2-dependent Mechanism*

    PubMed Central

    Shridas, Preetha; Zahoor, Lubna; Forrest, Kathy J.; Layne, Joseph D.; Webb, Nancy R.

    2014-01-01

    Group X secretory phospholipase A2 (GX sPLA2) potently hydrolyzes membrane phospholipids to release arachidonic acid (AA). While AA is an activator of glucose-stimulated insulin secretion (GSIS), its metabolite prostaglandin E2 (PGE2) is a known inhibitor. In this study, we determined that GX sPLA2 is expressed in insulin-producing cells of mouse pancreatic islets and investigated its role in beta cell function. GSIS was measured in vivo in wild-type (WT) and GX sPLA2-deficient (GX KO) mice and ex vivo using pancreatic islets isolated from WT and GX KO mice. GSIS was also assessed in vitro using mouse MIN6 pancreatic beta cells with or without GX sPLA2 overexpression or exogenous addition. GSIS was significantly higher in islets isolated from GX KO mice compared with islets from WT mice. Conversely, GSIS was lower in MIN6 cells overexpressing GX sPLA2 (MIN6-GX) compared with control (MIN6-C) cells. PGE2 production was significantly higher in MIN6-GX cells compared with MIN6-C cells and this was associated with significantly reduced cellular cAMP. The effect of GX sPLA2 on GSIS was abolished when cells were treated with NS398 (a COX-2 inhibitor) or L-798,106 (a PGE2-EP3 receptor antagonist). Consistent with enhanced beta cell function, GX KO mice showed significantly increased plasma insulin levels following glucose challenge and were protected from age-related reductions in GSIS and glucose tolerance compared with WT mice. We conclude that GX sPLA2 plays a previously unrecognized role in negatively regulating pancreatic insulin secretion by augmenting COX-2-dependent PGE2 production. PMID:25122761

  4. A catalytically-inactive snake venom Lys49 phospholipase A₂ homolog induces expression of cyclooxygenase-2 and production of prostaglandins through selected signaling pathways in macrophages.

    PubMed

    Moreira, Vanessa; de Castro Souto, Pollyana Cristina Maggio; Ramirez Vinolo, Marco Aurélio; Lomonte, Bruno; María Gutiérrez, José; Curi, Rui; Teixeira, Catarina

    2013-05-15

    The effects of a snake venom Lys-49 phospholipase A2 (PLA2) homolog named MT-II, devoid of enzymatic activity, on the biosynthesis of prostaglandins and protein expression of cyclooxygenase-2 (COX-2) and signaling pathways involved were evaluated in mouse macrophages in culture and in peritoneal cells ex vivo. Stimulation of macrophages with MT-II leads to production of prostaglandin D2 (PGD2) and prostaglandin E2 (PGE2) and protein expression of COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1). Inhibition of cytosolic PLA2 (cPLA2), but not Ca(2+) independent PLA2 (iPLA2) reduced release of PGD2 and PGE2 and expression of COX-2 induced by MT-II. Inhibition of nuclear factor κB (NF-κB) significantly reduced MT-II-induced PGE2, but not PGD2 production and COX-2 expression. Inhibitors of either protein kinase C (PKC), protein tyrosine kinase (PTK), or extracellular signal-regulated kinase (ERK) pathways abrogated MT-II-induced NF-κB activation and reduced COX-2 expression and PGE2 release, whereas the p38 mitogen-activated protein kinase (MAPK) inhibitor reduced MT-II-induced COX-2 expression and PGD2 production. Inhibition of phosphatidylinositol-3-kinase (PI3K) pathway abrogated MT-II-induced NF-κB activation, but affected neither prostaglandins production nor COX-2 expression. MT-II-induced production of PGD2 and PGE2 and COX-2 expression were also observed in vivo after intraperitoneal injection into mice. Collectively, our data demonstrate that a catalytically-inactive PLA2 homolog is capable of inducing prostaglandins biosynthesis and COX-2 expression in macrophages in both in vitro and in vivo models, indicating that the enzymatic activity of PLA2 is not necessary to trigger these effects. MT-II-activated NF-κB, cPLA2 and distinct protein kinases are the principal steps involved in these cellular events. PMID:23416211

  5. The G-765C promoter polymorphism in cyclooxygenase-2 (PTGS2), aspirin utilization and cardiovascular disease risk: the Atherosclerosis Risk in Communities (ARIC) study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cyclooxygenase-2 derived prostaglandins modulate cardiovascular disease risk. We sought to determine if the reduced function G-765C promoter polymorphism in PTGS2 was associated with incident coronary heart disease (CHD) or ischemic stroke risk, and if this was modified by aspirin utilization. Usin...

  6. P38 AND EGF RECEPTOR KINASE-MEDIATED ACTIVATION OF THE PHOSPHATIDYLINOSITOL 3-KINASE/AKT PATHWAY IS REQUIRED FOR ZN2+INDUCED CYCLOOXYGENASE-2 EXPRESSION

    EPA Science Inventory

    Cyclooxygenase 2 (COX-2) expression is induced by physiological and inflammatory stimuli. Regulation of COX-2 expression is stimulus- and cell type-specific. Exposure to Zn2+ has been associated with activation of multiple intracellular signaling pathways as well as the induction...

  7. Cyclooxygenase-2 in Endothelial and Vascular Smooth Muscle Cells Restrains Atherogenesis in Hyperlipidemic Mice

    PubMed Central

    Tang, Soon Yew; Monslow, James; Todd, Leslie; Lawson, John; Puré, Ellen; FitzGerald, Garret A.

    2014-01-01

    Background Placebo controlled trials of nonsteroidal antinflammatory drugs (NSAIDs) selective for inhibition of COX-2 reveal an emergent cardiovascular hazard in patients selected for low risk of heart disease. Postnatal global deletion of COX-2 accelerates atherogenesis in hyperlipidemic mice, a process delayed by selective enzyme deletion in macrophages. Methods and Results Here, selective depletion of COX-2 in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) depressed biosynthesis of prostaglandin (PG)I2 and PGE2, elevated blood pressure and accelerated atherogenesis in Ldlr knockout (KO) mice. Deletion of COX-2 in VSMCs and ECs coincided with an increase in COX-2 expression in lesional macrophages and increased biosynthesis of thromboxane. Increased accumulation of less organized intimal collagen, laminin, α-smooth muscle actin and matrix-rich fibrosis was also apparent in lesions of the mutants. Conclusions Although atherogenesis is accelerated in global COX-2 KOs, consistent with evidence of risk transformation during chronic NSAID administration, this masks the contrasting effects of enzyme depletion in macrophages versus VSMCs and ECs. Targeting delivery of COX-2 inhibitors to macrophages may conserve their efficacy while limiting cardiovascular risk. PMID:24519928

  8. Cyclooxygenase-2 knockdown using retinoic acid chalcone (RAC), a promising therapeutic strategy for colon cancer

    PubMed Central

    Jiang, Chao; Wang, Qiong; Xu, Zhe; Li, Wei-Su; Chen, Che; Yao, Xue-Quan; Liu, Fu-Kun

    2015-01-01

    Retinoic acid is an effective agent in the treatment of epithelial and hematological malignancies. The present study demonstrates that retinoic acid chalcone (RAC), an analogue of retinoic acid inhibits cell proliferation and induces apoptosis in HCT-15 and CT26.WT colon cancer cell lines. In HCT-15 cells the percentage of apoptotic cells increased from 32.4 ± 3, 45.0 ± 3 to 72.6 ± 5% respectively at 10, 15 and 20 μg/mL compared to 3.7% in control. Similarly in CT26.WT cells the percentage increased from 28.6 ± 3, 41.2 ± 3 to 65.4 ± 5% on treatment with 10, 15 and 20 μg/mL concentrations of RAC after 72 h compared to 2.9 ± 1% in control. Western blotting, fluorescence-activated cell sorting analysis and reverse transcription-PCR assays were used to investigate these effects. RAC inhibited the overexpression of COX-2, PGE2 and PGE2 receptor (EP1 and EP4) in the colon cancer cell lines. RAC mediated inhibition of cell growth and induction of apoptosis through COX-2 inhibition was also confirmed by treating the HCT-15 and CT26.WT colon cancer cells with COX-2 inhibitor, indomethacin and transfection of cells with COX-2 small interfering RNA. In nude mice with tumor xenografts, treatment with RAC-supplemented diet caused inhibition of COX-2, PGE2, and PGE2 receptors (EP1, EP3, and EP4) in tumors. Thus RAC can be a potential candidate for the treatment of colon cancer through the inhibition of COX-2 expression and subsequent inhibition of PGE2 and PGE2 receptors. PMID:26269760

  9. Misoprostol Reverse Hippocampal Neuron Cyclooxygenase-2 Downstream Signaling Imbalance in Aluminum-Overload Rats

    PubMed Central

    Guo, Yuanxin; Lei, Wenjuan; Wang, Jianfeng; Hu, Xinyue; Wei, Yuling; Ji, Chaonan; Yang, Junqing

    2016-01-01

    Although COX-2 inhibition in animal models of neurodegenerative diseases has shown neuroprotection, recent studies have revealed some serious side effects (ulcers, bleeding, fatal cerebrovascular diseases etc.) and the limited benefits of COX-2 inhibitors. A more focused approach is necessary to explore the therapeutic effect of the COX downstream signaling pathway in neurological research. The aim of this study was to explore the alterations of the PGES-PGE2-EP signal pathway and the effect of misoprostol on neurodegeneration by chronic aluminum-overload in rats. Adult rats were treated by intragastric administration of aluminum gluconate. The PGE2 content and expression of PGES and EPs in the hippocampi of rats were detected using ELISA, q-PCR and Western blot analysis, respectively. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the rat hippocampi were also detected. The misoprostol treatment dose-dependently improved spatial learning and memory function as well as healing after hippocampal neuron damage induced by chronic aluminum-overload in rats. Meanwhile, the administration of misoprostol resulted in a decrease in the PGE2 level and down-regulation of the mPGES-1, EP2 and EP4 expression levels, while there was a dose-dependent up-regulation of EP3 expression. These results suggest that misoprostol possesses a neuroprotective property, and the mechanism involves affecting the EP3 level and reducing the endogenous production of PGE2 through a negative feedback mechanism, increasing the EP3 expression level, decreasing the EP2 and EP4 expression levels, and rebuilding the mPGES-1-PGE2-EP1-4 signal pathway balance. In this way, misoprostol has a counteractive effect on oxidant stress and inflammation in the central nervous system. The PGES-PGE2-EPs signaling pathway is a potential therapeutic strategy for treating neurodegeneration in patients. PMID:27033056

  10. Vitamin D Induces Cyclooxygenase 2 Dependent Prostaglandin E2 Synthesis in HaCaT Keratinocytes.

    PubMed

    Ravid, Amiram; Shenker, Ohad; Buchner-Maman, Efrat; Rotem, Carmela; Koren, Ruth

    2016-04-01

    The active metabolite of vitamin D calcitriol and its analogs are well-known for their anti-inflammatory action in the skin, while their main side effect associated with topical treatment of inflammatory disorders is irritant contact dermatitis. Prostaglandin E2 (PGE2 ) is pro-inflammatory at the onset of inflammation and anti-inflammatory at its resolution. We hypothesized that induction of PGE2 synthesis by calcitriol in epidermal keratinocytes may contribute both to its pro-inflammatory and anti-inflammatory effects on the skin. Treatment of human immortalized HaCaT keratinocytes with calcitriol (3-100 nM, 2-24 h) increased PGE2 production due to increased mRNA and protein expression of COX-2, but not to increase of COX-1 or release of arachidonic acid. The effect of calcitriol on COX-2 mRNA was observed also in primary human keratinocytes. The increase in COX-2 mRNA is associated with COX-2 transcript stabilization. Calcitriol exerts this effect by a rapid (2 h) and protein synthesis independent mode of action that is dependent on PKC and Src kinase activities. Treatment with a COX-2 inhibitor partially prevented the attenuation of the keratinocyte inflammatory response by calcitriol. We conclude that upregulation of COX-2 expression with the consequent increase in PGE2 synthesis may be one of the mechanisms explaining the Janus face of calcitriol as both a promoter and attenuator of cutaneous inflammation. J. Cell. Physiol. 231: 837-843, 2016. © 2015 Wiley Periodicals, Inc. PMID:26280673

  11. Misoprostol Reverse Hippocampal Neuron Cyclooxygenase-2 Downstream Signaling Imbalance in Aluminum-Overload Rats.

    PubMed

    Guo, Yuanxin; Lei, Wenjuan; Wang, Jianfeng; Hu, Xinyue; Wei, Yuling; Ji, Chaonan; Yang, Junqing

    2016-01-01

    Although COX-2 inhibition in animal models of neurodegenerative diseases has shown neuroprotection, recent studies have revealed some serious side effects (ulcers, bleeding, fatal cerebrovascular diseases etc.) and the limited benefits of COX-2 inhibitors. A more focused approach is necessary to explore the therapeutic effect of the COX downstream signaling pathway in neurological research. The aim of this study was to explore the alterations of the PGES-PGE2-EP signal pathway and the effect of misoprostol on neurodegeneration by chronic aluminum-overload in rats. Adult rats were treated by intragastric administration of aluminum gluconate. The PGE2 content and expression of PGES and EPs in the hippocampi of rats were detected using ELISA, q-PCR and Western blot analysis, respectively. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the rat hippocampi were also detected. The misoprostol treatment dose-dependently improved spatial learning and memory function as well as healing after hippocampal neuron damage induced by chronic aluminum-overload in rats. Meanwhile, the administration of misoprostol resulted in a decrease in the PGE2 level and down-regulation of the mPGES-1, EP2 and EP4 expression levels, while there was a dosedependent up-regulation of EP3 expression. These results suggest that misoprostol possesses a neuroprotective property, and the mechanism involves affecting the EP3 level and reducing the endogenous production of PGE2 through a negative feedback mechanism, increasing the EP3 expression level, decreasing the EP2 and EP4 expression levels, and rebuilding the mPGES-1-PGE2-EP1-4 signal pathway balance. In this way, misoprostol has a counteractive effect on oxidant stress and inflammation in the central nervous system. The PGES-PGE2-EPs signaling pathway is a potential therapeutic strategy for treating neurodegeneration in patients. PMID:27033056

  12. Nicotine impairs cyclooxygenase-2-dependent kinin-receptor-mediated murine airway relaxations

    SciTech Connect

    Xu, Yuan Cardell, Lars-Olaf

    2014-02-15

    Introduction: Cigarette smoke induces local inflammation and airway hyperreactivity. In asthmatics, it worsens the symptoms and increases the risk for exacerbation. The present study investigates the effects of nicotine on airway relaxations in isolated murine tracheal segments. Methods: Segments were cultured for 24 h in the presence of vehicle, nicotine (10 μM) and/or dexamethasone (1 μM). Airway relaxations were assessed in myographs after pre-contraction with carbachol (1 μM). Kinin receptors, cyclooxygenase (COX) and inflammatory mediator expressions were assessed by real-time PCR and confocal-microscopy-based immunohistochemistry. Results: The organ culture procedure markedly increased bradykinin- (selective B{sub 2} receptor agonist) and des-Arg{sup 9}-bradykinin- (selective B{sub 1} receptor agonist) induced relaxations, and slightly increased relaxation induced by isoprenaline, but not that induced by PGE{sub 2}. The kinin receptor mediated relaxations were epithelium-, COX-2- and EP2-receptor-dependent and accompanied by drastically enhanced mRNA levels of kinin receptors, as well as inflammatory mediators MCP-1 and iNOS. Increase in COX-2 and mPGES-1 was verified both at mRNA and protein levels. Nicotine selectively suppressed the organ-culture-enhanced relaxations induced by des-Arg{sup 9}-bradykinin and bradykinin, at the same time reducing mPGES-1 mRNA and protein expressions. α7-nicotinic acetylcholine receptor inhibitors α-bungarotoxin and MG624 both blocked the nicotine effects on kinin B{sub 2} receptors, but not those on B{sub 1}. Dexamethasone completely abolished kinin-induced relaxations. Conclusion: It is tempting to conclude that a local inflammatory process per se could have a bronchoprotective component by increasing COX-2 mediated airway relaxations and that nicotine could impede this safety mechanism. Dexamethasone further reduced airway inflammation together with relaxations. This might contribute to the steroid resistance seen in

  13. Role of cyclooxygenase 2 in protein kinase C beta II-mediated colon carcinogenesis.

    PubMed

    Yu, Wangsheng; Murray, Nicole R; Weems, Capella; Chen, Lu; Guo, Huiping; Ethridge, Richard; Ceci, Jeffrey D; Evers, B Mark; Thompson, E Aubrey; Fields, Alan P

    2003-03-28

    Elevated expression of protein kinase C beta II (PKC beta II) is an early promotive event in colon carcinogenesis (Gokmen-Polar, Y., Murray, N. R., Velasco, M. A., Gatalica, Z., and Fields, A. P. (2001) Cancer Res. 61, 1375-1381). Expression of PKC beta II in the colon of transgenic mice leads to hyperproliferation and increased susceptibility to colon carcinogenesis due, at least in part, to repression of transforming growth factor beta type II receptor (TGF-beta RII) expression (Murray, N. R., Davidson, L. A., Chapkin, R. S., Gustafson, W. C., Schattenberg, D. G., and Fields, A. P. (1999) J. Cell Biol., 145, 699-711). Here we report that PKC beta II induces the expression of cyclooxygenase type 2 (Cox-2) in rat intestinal epithelial (RIE) cells in vitro and in transgenic PKC beta II mice in vivo. Cox-2 mRNA increases more than 10-fold with corresponding increases in Cox-2 protein and PGE2 production in RIE/PKC beta II cells. PKC beta II activates the Cox-2 promoter by 2- to 3-fold and stabilizes Cox-2 mRNA by at least 4-fold. The selective Cox-2 inhibitor Celecoxib restores expression of TGF-beta RII both in vitro and in vivo and restores TGF beta-mediated transcription in RIE/PKC beta II cells. Likewise, the omega-3 fatty acid eicosapentaenoic acid (EPA), which inhibits PKC beta II activity and colon carcinogenesis, causes inhibition of Cox-2 protein expression, re-expression of TGF-beta RII, and restoration of TGF-beta1-mediated transcription in RIE/PKC beta II cells. Our data demonstrate that PKC beta II promotes colon cancer, at least in part, through induction of Cox-2, suppression of TGF-beta signaling, and establishment of a TGF-beta-resistant, hyperproliferative state in the colonic epithelium. Our data define a procarcinogenic PKC beta II --> Cox-2 --> TGF-beta signaling axis within the colonic epithelium, and provide a molecular mechanism by which dietary omega-3 fatty acids and nonsteroidal antiinflammatory agents such as Celecoxib suppress colon

  14. Gastrodin Inhibits Expression of Inducible NO Synthase, Cyclooxygenase-2 and Proinflammatory Cytokines in Cultured LPS-Stimulated Microglia via MAPK Pathways

    PubMed Central

    Zhong, Lian-Mei; Li, Yue-Min; Zhang, Wei; Bian, Li-Gong; Ai, Qing-Long; Liu, Yi-Dan; Sun, Jun; Lu, Di

    2011-01-01

    Background Microglial activation plays an important role in neurodegenerative diseases by producing several proinflammatory enzymes and proinflammatory cytokines. The phenolic glucoside gastrodin, a main constituent of a Chinese herbal medicine, has been known to display anti-inflammatory properties. The current study investigates the potential mechanisms whereby gastrodin affects the expression of potentially pro-inflammatory proteins by cultured murine microglial BV-2 cells stimulated with lipopolysaccharide (LPS). Methodology/Principal Findings BV-2 cells were pretreated with gastrodin (30, 40, and 60 µM) for 1 h and then stimulated with LPS (1 µg/ml) for another 4 h. The effects on proinflammatory enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and proinflammatory cytokines, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β), are analysed by double-immunofluorescence labeling and RT-PCR assay. To reveal the mechanisms of action of gastrodin we investigated the involvement of mitogen-activated protein kinases (MAPKs) cascades and their downstream transcription factors, nuclear factor-κB (NF-κB) and cyclic AMP-responsive element (CRE)-binding protein (CREB). Gastrodin significantly reduced the LPS-induced protein and mRNA expression levels of iNOS, COX-2, TNF-α, IL-1β and NF-κB. LPS (1 µg/ml, 30 min)-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK) and this was inhibited by pretreatment of BV-2 cells with different concentrations of gastrodin (30, 40, and 60 µM). In addition, gastrodin blocked LPS-induced phosphorylation of inhibitor κB-α (IκB-α) (and hence the activation of NF-κB) and of CREB, respectively. Conclusion and Implications This study indicates that gastrodin significantly attenuate levels of neurotoxic proinflammatory mediators and proinflammatory cytokines by inhibition of

  15. Temporal expression of the PGE2 synthetic system in the kidney is associated with the time frame of renal developmental vulnerability to cyclooxygenase-2 inhibition.

    PubMed

    Frölich, Stefanie; Olliges, Anke; Kern, Niklas; Schreiber, Yannik; Narumiya, Shuh; Nüsing, Rolf M

    2012-07-15

    Pharmacological blockade of cyclooxygenase-2 (COX-2) causes impairment of kidney development. The present study was aimed at determining temporal expression pattern and activity of the PGE(2) synthetic pathway during postnatal nephrogenesis in mice and its association to the time window sensitive to COX-2 inhibition. During the first 10 days after birth, we observed transient induction of mRNA and protein for microsomal PGE synthase (mPGES)-1 between postnatal days 4 (P4) and P8, but not for mPGES-2 or cytosolic PGE synthase (cPGES). PGE(2) synthetic activity using arachidonic acid and PGH(2) as substrates and also urinary excretion of PGE(2) were enhanced during this time frame. In parallel to the PGE(2) system, COX-2 but not COX-1 expression was also transiently induced. Studying glomerulogenesis in EP receptor knockout mice revealed a reduction in glomerular size in EP1(-/-), EP2(-/-), and EP4(-/-) mice, supporting the developmental role of PGE(2). The most vulnerable time window to COX-2 inhibition by SC-236 was found closely related to the temporal expression of COX-2 and mPGES-1. The strongest effects of COX-2 inhibition were achieved following 8 days of drug administration. Similar developmental damage was caused by application of rofecoxib, but not by the COX-1-selective inhibitor SC-560. COX-2 inhibition starting after P10 has had no effect on the size of glomeruli or on the relative number of superficial glomeruli; however, growth of the renal cortex was significantly diminished, indicating the requirement of COX-2 activity after P10. Effects of COX-2 inhibition on renal cell differentiation and on renal fibrosis needed a prolonged time of exposition of at least 10 days. In conclusion, temporal expression of the PGE(2) synthetic system coincides with the most vulnerable age interval for the induction of irreversible renal abnormalities. We assume that mPGES-1 is coregulated with COX-2 for PGE(2) synthesis to orchestrate postnatal kidney development and

  16. Cyclooxygenase-2/prostaglandin D2/CRTH2 pathway mediates double-stranded RNA-induced enhancement of allergic airway inflammation.

    PubMed

    Shiraishi, Yoshiki; Asano, Koichiro; Niimi, Kyoko; Fukunaga, Koichi; Wakaki, Misa; Kagyo, Junko; Takihara, Takahisa; Ueda, Soichiro; Nakajima, Takeshi; Oguma, Tsuyoshi; Suzuki, Yusuke; Shiomi, Tetsuya; Sayama, Koichi; Kagawa, Shizuko; Ikeda, Eiji; Hirai, Hiroyuki; Nagata, Kinya; Nakamura, Masataka; Miyasho, Taku; Ishizaka, Akitoshi

    2008-01-01

    Respiratory RNA viruses responsible for the common cold often worsen airway inflammation and bronchial responsiveness, two characteristic features of human asthma. We studied the effects of dsRNA, a nucleotide synthesized during viral replication, on airway inflammation and bronchial hyperresponsiveness in murine models of asthma. Intratracheal instillation of poly I:C, a synthetic dsRNA, increased the airway eosinophilia and enhanced bronchial hyperresponsiveness to methacholine in OVA-sensitized, exposed rats. These changes were associated with induction of cyclooxygenase-2 (COX-2) expression and COX-2-dependent PGD2 synthesis in the lungs, particularly in alveolar macrophages. The direct intratracheal instillation of PGD2 enhanced the eosinophilic inflammation in OVA-exposed animals, whereas pretreatment with a dual antagonist against the PGD2 receptor-(CRTH2) and the thromboxane A2 receptor, but not with a thromboxane A2 receptor-specific antagonist, nearly completely eliminated the dsRNA-induced worsening of airway inflammation and bronchial hyperresponsiveness. CRTH2-deficient mice had the same degree of allergen-induced airway eosinophilia as wild-type mice, but they did not exhibit a dsRNA-induced increase in eosinophil accumulation. Our data demonstrate that COX-2-dependent production of PGD2 followed by eosinophil recruitment into the airways via a CRTH2 receptor are the major pathogenetic factors responsible for the dsRNA-induced enhancement of airway inflammation and responsiveness. PMID:18097056

  17. K-Ras and cyclooxygenase-2 coactivation augments intraductal papillary mucinous neoplasm and Notch1 mimicking human pancreas lesions

    PubMed Central

    Chiblak, Sara; Steinbauer, Brigitte; Pohl-Arnold, Andrea; Kucher, Dagmar; Abdollahi, Amir; Schwager, Christian; Höft, Birgit; Esposito, Irene; Müller-Decker, Karin

    2016-01-01

    Mutational activation of K-Ras is an initiating event of pancreatic ductal adenocarcinomas (PDAC) that may develop either from pancreatic intraepithelial neoplasia (PanIN) or intraductal papillary mucinous neoplasms (IPMN). Cyclooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) is causally related to pancreatic carcinogenesis. Here, we deciphered the impact of COX-2, a key modulator of inflammation, in concert with active mutant K-RasG12D on tumor burden and gene expression signature using compound mutant mouse lines. Concomitant activation of COX-2 and K-RasG12D accelerated the progression of pancreatic intraepithelial lesions predominantly with a cystic papillary phenotype resembling human IPMN. Transcriptomes derived from laser capture microdissected preneoplastic lesions of single and compound mutants revealed a signature that was significantly enriched in Notch1 signaling components. In vitro, Notch1 signaling was COX-2-dependent. In line with these findings, human IPMN stratified into intestinal, gastric and pancreatobillary types displayed Notch1 immunosignals with high prevalence, especially in the gastric lesions. In conclusion, a yet unknown link between activated Ras, protumorigenic COX-2 and Notch1 in IPMN onset was unraveled. PMID:27381829

  18. Low sodium and furosemide-induced stimulation of the renin system in man is mediated by cyclooxygenase 2.

    PubMed

    Kammerl, M C; Nüsing, R M; Schweda, F; Endemann, D; Stubanus, M; Kees, F; Lackner, K J; Fischereder, M; Krämer, B K

    2001-11-01

    The aim of this study was to examine the effects of highly selective inhibition of cyclooxygenase 2 (COX-2) with rofecoxib on the renin system during long-term stimulation and after short-term stimulation. Six healthy male volunteers received, in a randomized crossover design, a low-sodium diet for days 1 through 9 with or without 25 mg rofecoxib twice daily on days 5 through 9 and, in addition, 20 mg of furosemide intravenously on day 8. Plasma renin activity increased 2 to 3 times over baseline with a low-sodium diet and 5 times over baseline 30 minutes after intravenous furosemide; it was still elevated nearly 5 times on day 9. These effects were completely blocked by rofecoxib. Plasma aldosterone and urinary aldosterone concentrations basically reflected the findings with plasma renin activity. Urinary sodium excretion decreased during a low-sodium diet and increased after intravenous furosemide without being significantly affected by rofecoxib. We have concluded that low-sodium and furosemide-stimulated renin and aldosterone secretion is completely blocked in healthy volunteers during COX-2 inhibition with rofecoxib, suggesting that intact COX-2 is of major importance for stimulation of the renin system under these conditions in man. PMID:11719734

  19. Granulocyte-macrophage colony-stimulating factor amplifies lipopolysaccharide-induced bronchoconstriction by a neutrophil- and cyclooxygenase 2-dependent mechanism.

    PubMed

    Wollin, L; Uhlig, S; Nüsing, R; Wendel, A

    2001-02-01

    Granulocyte-macrophage colony-stimulating factor (GM-CSF) is used to ameliorate neutropenia in patients after antineoplastic treatment. It has also been suggested as an adjunct treatment in septic patients; however, the recruitment and priming of leukocytes by GM-CSF bears the hazard of a hyperinflammatory response. In particular, the role of GM-CSF in pulmonary functions in septic lungs is still unclear. Therefore, we pretreated rats in vivo with GM-CSF (50 microg/kg, intravenous) and assessed the pulmonary functions of their subsequently prepared isolated perfused lungs when exposed to subtoxic concentrations of lipopolysaccharide (LPS, 2 microg/ml). These lungs showed enhanced expression of cyclooxygenase 2 (COX-2), a significant increase in thromboxane (TX) and tumor necrosis factor (TNF) release into the venous perfusate, and bronchoconstriction. COX-2 inhibition or blocking of the TX receptor abolished the GM-CSF/LPS-induced bronchoconstriction, but not the TNF release. Neutralizing antibodies against TNF did not prevent GM-CSF/LPS-induced bronchoconstriction. After GM-CSF pretreatment, massive neutrophil invasion into the lung occurred. Neutropenic rats were protected against GM-CSF/ LPS-induced lung injury. Similar results were obtained in rats pretreated with G-CSF instead of GM-CSF. We conclude that GM-CSF pretreatment exacerbates pulmonary injury by low-dose LPS via COX-2 expression, TX release, and bronchoconstriction by initiating neutrophil invasion and activation. PMID:11179120

  20. Uteroplacental insufficiency alters nephrogenesis and downregulates cyclooxygenase-2 expression in a model of IUGR with adult-onset hypertension.

    PubMed

    Baserga, Mariana; Hale, Merica A; Wang, Zheng Ming; Yu, Xing; Callaway, Christopher W; McKnight, Robert A; Lane, Robert H

    2007-05-01

    Clinical and animal studies indicate that intrauterine growth restriction (IUGR) following uteroplacental insufficiency (UPI) reduces nephron number and predisposes toward renal insufficiency early in life and increased risk of adult-onset hypertension. In this study, we hypothesized that the inducible enzyme cyclooxygenase-2 (COX-2), a pivotal protein in nephrogenesis, constitutes a mechanism through which UPI and subsequent glucocorticoid overexposure can decrease nephron number. We further hypothesized that UPI downregulates the key enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), which converts corticosterone to inert 11-dehydrocorticosterone, thereby protecting both the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR) from the actions of corticosterone. Following bilateral uterine ligation on the pregnant rat, UPI significantly decreased renal COX-2, 11beta-HSD2, and GR mRNA and protein levels, but upregulated expression of MR at birth. At day 21 of life, 11beta-HSD2, GR, and also MR mRNA and protein levels were downregulated. UPI did not affect blood pressures (BP) at day 21 of life but significantly increased systolic BP in both genders at day 140. We conclude that in our animal model, UPI decreases fetal COX-2 expression during a period of active nephrogenesis in the IUGR rat, which is also characterized by decreased nephron number and adult-onset hypertension. PMID:17272666

  1. K-Ras and cyclooxygenase-2 coactivation augments intraductal papillary mucinous neoplasm and Notch1 mimicking human pancreas lesions.

    PubMed

    Chiblak, Sara; Steinbauer, Brigitte; Pohl-Arnold, Andrea; Kucher, Dagmar; Abdollahi, Amir; Schwager, Christian; Höft, Birgit; Esposito, Irene; Müller-Decker, Karin

    2016-01-01

    Mutational activation of K-Ras is an initiating event of pancreatic ductal adenocarcinomas (PDAC) that may develop either from pancreatic intraepithelial neoplasia (PanIN) or intraductal papillary mucinous neoplasms (IPMN). Cyclooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) is causally related to pancreatic carcinogenesis. Here, we deciphered the impact of COX-2, a key modulator of inflammation, in concert with active mutant K-Ras(G12D) on tumor burden and gene expression signature using compound mutant mouse lines. Concomitant activation of COX-2 and K-Ras(G12D) accelerated the progression of pancreatic intraepithelial lesions predominantly with a cystic papillary phenotype resembling human IPMN. Transcriptomes derived from laser capture microdissected preneoplastic lesions of single and compound mutants revealed a signature that was significantly enriched in Notch1 signaling components. In vitro, Notch1 signaling was COX-2-dependent. In line with these findings, human IPMN stratified into intestinal, gastric and pancreatobillary types displayed Notch1 immunosignals with high prevalence, especially in the gastric lesions. In conclusion, a yet unknown link between activated Ras, protumorigenic COX-2 and Notch1 in IPMN onset was unraveled. PMID:27381829

  2. Cyclooxygenase-2-dependent phosphorylation of the pro-apoptotic protein Bad inhibits tonicity-induced apoptosis in renal medullary cells.

    PubMed

    Küper, Christoph; Bartels, Helmut; Beck, Franz-X; Neuhofer, Wolfgang

    2011-11-01

    During antidiuresis, cell survival in the renal medulla requires cyclooxygenase-2 (COX-2) activity. We have recently found that prostaglandin E2 (PGE2) promotes cell survival by phosphorylation and, hence, inactivation of the pro-apoptotic protein Bad during hypertonic stress in Madin-Darby canine kidney (MDCK) cells in vitro. Here we determine the role of COX-2-derived PGE(2) on phosphorylation of Bad and medullary apoptosis in vivo using COX-2-deficient mice. Both wild-type and COX-2-knockout mice constitutively expressed Bad in tubular epithelial cells of the renal medulla. Dehydration caused a robust increase in papillary COX-2 expression, PGE2 excretion, and Bad phosphorylation in wild-type, but not in the knockout mice. The abundance of cleaved caspase-3, a marker of apoptosis, was significantly higher in papillary homogenates, especially in tubular epithelial cells of the knockout mice. Knockdown of Bad in MDCK cells decreased tonicity-induced caspase-3 activation. Furthermore, the addition of PGE2 to cells with knockdown of Bad had no effect on caspase-3 activation; however, PGE2 caused phosphorylation of Bad and substantially improved cell survival in mock-transfected cells. Thus, tonicity-induced COX-2 expression and PGE2 synthesis in the renal medulla entails phosphorylation and inactivation of the pro-apoptotic protein Bad, thereby counteracting apoptosis in renal medullary epithelial cells. PMID:21716255

  3. Systematic study of constitutive cyclooxygenase-2 expression: Role of NF-κB and NFAT transcriptional pathways

    PubMed Central

    Kirkby, Nicholas S.; Chan, Melissa V.; Zaiss, Anne K.; Garcia-Vaz, Eliana; Jiao, Jing; Berglund, Lisa M.; Verdu, Elena F.; Ahmetaj-Shala, Blerina; Wallace, John L.; Herschman, Harvey R.; Gomez, Maria F.; Mitchell, Jane A.

    2016-01-01

    Cyclooxygenase-2 (COX-2) is an inducible enzyme that drives inflammation and is the therapeutic target for widely used nonsteroidal antiinflammatory drugs (NSAIDs). However, COX-2 is also constitutively expressed, in the absence of overt inflammation, with a specific tissue distribution that includes the kidney, gastrointestinal tract, brain, and thymus. Constitutive COX-2 expression is therapeutically important because NSAIDs cause cardiovascular and renal side effects in otherwise healthy individuals. These side effects are now of major concern globally. However, the pathways driving constitutive COX-2 expression remain poorly understood. Here we show that in the kidney and other sites, constitutive COX-2 expression is a sterile response, independent of commensal microorganisms and not associated with activity of the inflammatory transcription factor NF-κB. Instead, COX-2 expression in the kidney but not other regions colocalized with nuclear factor of activated T cells (NFAT) transcription factor activity and was sensitive to inhibition of calcineurin-dependent NFAT activation. However, calcineurin/NFAT regulation did not contribute to constitutive expression elsewhere or to inflammatory COX-2 induction at any site. These data address the mechanisms driving constitutive COX-2 and suggest that by targeting transcription it may be possible to develop antiinflammatory therapies that spare the constitutive expression necessary for normal homeostatic functions, including those important to the cardiovascular-renal system. PMID:26712011

  4. Inhibition of cyclooxygenase-2 alleviates liver cirrhosis via improvement of the dysfunctional gut-liver axis in rats.

    PubMed

    Gao, Jin-Hang; Wen, Shi-Lei; Tong, Huan; Wang, Chun-Hui; Yang, Wen-Juan; Tang, Shi-Hang; Yan, Zhao-Ping; Tai, Yang; Ye, Cheng; Liu, Rui; Huang, Zhi-Yin; Tang, Ying-Mei; Yang, Jin-Hui; Tang, Cheng-Wei

    2016-06-01

    Inflammatory transport through the gut-liver axis may facilitate liver cirrhosis. Cyclooxygenase-2 (COX-2) has been considered as one of the important molecules that regulates intestinal epithelial barrier function. This study was aimed to test the hypothesis that inhibition of COX-2 by celecoxib might alleviate liver cirrhosis via reduction of intestinal inflammatory transport in thiacetamide (TAA) rat model. COX-2/prostaglandin E2 (PGE2)/EP-2/p-ERK integrated signal pathways regulated the expressions of intestinal zonula occludens-1 (ZO-1) and E-cadherin, which maintain the function of intestinal epithelial barrier. Celecoxib not only decreased the intestinal permeability to a 4-kDa FITC-dextran but also significantly increased expressions of ZO-1 and E-cadherin. When celecoxib greatly decreased intestinal levels of LPS, TNF-α, and IL-6, it significantly enhanced T cell subsets reduced by TAA. As a result, liver fibrosis induced by TAA was significantly alleviated in the celecoxib group. These data indicated that celecoxib improved the integrity of intestinal epithelial barrier, blocked inflammatory transport through the dysfunctional gut-liver axis, and ameliorated the progress of liver cirrhosis. PMID:27056726

  5. Expression of prostaglandin synthesizing enzymes (cyclooxygenase 1 and cyclooxygenase 2) in the ovary of the ostrich (Struthio camelus).

    PubMed

    Rodler, Daniela; Sinowatz, Fred

    2015-01-01

    Cyclooxygenase is the rate limiting enzyme in the production of prostaglandins. In birds two isoforms are present: cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). Despite evidence implicating that cyclooxygenases and PGs are critical factors in female reproduction in birds, little is known about COX expression in the avian ovary. In birds, cyclooxygenases have been studied in very few species only. In this study we report on the expression of COX-1 and COX-2 in the ovary of the ostrich (Struthio camelus) using immunohistochemistry and non-radioactive in situ hybridization techniques. Our results demonstrate that COX-1 is strongly expressed in the cytoplasm of oocytes of previtellogenic follicles, whereas COX-2 shows the strongest immunostaining in the granulosa cells of previtellogenic follicles. The signals of both isoenzymes fade significantly with increasing diameter and finally nearly vanish in the vitellogenic follicles with a size >1.8 cm. This expression pattern in the ostrich (S. camelus) is, therefore, completely different from the localization of COX-1 and COX-2 in the hen (Gallus gallus), a finding which also suggests different functions of the cyclooxygenases in the ostrich species. Non-radioactive in situ hybridization confirmed that COX-1 is synthesized in the ooplasm and COX-2 in the granulosa layers of early previtellogenic follicles. According to the results of this study it appears unlikely that COX-1 or COX-2 play a major role in ovulation and oviposition in the ostrich. PMID:25528171

  6. Genetic association of cyclooxygenase-2 gene polymorphisms with Parkinson’s disease susceptibility in Chinese Han population

    PubMed Central

    Dai, Yi; Wu, Yuquan; Li, Yansheng

    2015-01-01

    Objective: The aim of this study was to explore the genetic association of cyclooxygenase-2 (COX2) gene promoter region polymorphisms with Parkinson’s disease (PD) susceptibility in Chinese Han population. Methods: The genotyping of COX2 gene polymorphisms was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 122 patients with PD and 120 healthy persons. The association strength of gene polymorphism with disease was measured by odds ratio (OR) and 95% confidence interval (95% CI) calculated using χ2 test which also evaluated the Hardy-Weinberg equilibrium (HWE) of gene polymorphism in controls. The linkage disequilibrium and haplotype were also analyzed as evidence in the analysis of association. Results: On condition that the genotypes distributions of COX2 -1290A>G, -1195G>A, -765G>C in the control group all conformed to HWE, however, only the homozygous genotype AA of -1195G>A polymorphism showed an association with PD (OR=0.432, 95% CI=0.196-0.950). In addition, in haplotype analysis, G-A-C haplotype frequency in cases was significantly lower than the controls, compared with the common haplotype A-G-G (P=0.031, OR=0.375, 95% CI=0.149-0.940). Conclusions: COX2 -1195G>A polymorphism might play a protective role in the onset of PD and G-A-C haplotype in this three promoter region polymorphisms also showed a negative association. PMID:26722563

  7. Low expression of microRNA-143 is related to degenerative scoliosis possibly by regulation of cyclooxygenase-2 expression

    PubMed Central

    Zheng, Jie; Yang, Yonghong; Zhao, Kefeng; Wang, Ran

    2015-01-01

    Aims: This study is to determine if expression level of microRNA-143 (miR-143) and cyclooxygenase-2 (COX-2) are related to the occurrence and development of degenerative scoliosis. Methods: A total of 30 patients with degenerative scoliosis, 30 patients with adolescent idiopathic scoliosis were enrolled in this study. For control, 30 patients with spinal burst fractures were also enrolled in this study. Real-time PCR and western blotting was performed to measure the expression levels of COX-2 in intervertebral disc tissues, peripheral blood and cerebrospinal. Expression levels of miR-143 in intervertebral disc tissues, peripheral blood and cerebrospinal were detected by real-time PCR. Results: The expression levels of COX-2 were increased in intervertebral disc tissues, peripheral blood and cerebrospinal of patients with degenerative scoliosis when compared with those of patients with adolescent idiopathic scoliosis and spinal burst fractures (P < 0.05). However, the expression levels of miR-143 were decreased in intervertebral disc tissues, peripheral blood and cerebrospinal of patients with degenerative scoliosis when compared with those of patients with adolescent idiopathic scoliosis and spinal burst fractures (P < 0.05). Conclusions: COX-2 is highly expressed whereas miR-143 is lowly expressed in patients with degenerative scoliosis. Decreased expression of miR-143 may be related to the aggravation of degenerative scoliosis by regulation of COX-2. PMID:26064322

  8. Cyclooxygenase 2 (rs2745557) Polymorphism and the Susceptibility to Benign Prostate Hyperplasia and Prostate Cancer in Egyptians.

    PubMed

    Fawzy, Mohamed S; Elfayoumi, Abdel-Rahman; Mohamed, Randa H; Fatah, Ihab R Abdel; Saadawy, Sara F

    2016-06-01

    Cyclooxygenase-2 (COX-2), an inducible isoform of cyclooxygenase, has been reported to be correlated with tumorigenesis, tumor progression, and metastasis. We aimed to evaluate the association between COX-2 (rs2745557) polymorphism and prostate cancer (PCa), benign prostate hyperplasia (BPH) risk. We also assessed the influence of other risk factors such as obesity, smoking, diabetes in modulating the risk of PCa in Egyptian men. COX-2 (rs2745557) was genotyped in 112 PC patients, 111 BPH and 120 subjects as a control group. COX-2 and PSA levels were measured by ELISA. We found that GG genotype was associated with a 17-fold increased risk for PCa and 20-fold increased the risk for BPH more than AA genotype. Also, G allele carriers of COX-2 were associated with metastatic cancer (OR = 1.3, P < 0.05) and disease aggressiveness (OR = 3.5, P < 0.001). The coexistence of obesity, smoking, or diabetes with GG genotype may lead to increasing the risk of developing BPH (OR = 3.3, 4, and 2.7, respectively) and of developing PCa (OR = 2.9, 4.9, and 3.2, respectively). Our results showed evidence suggesting the involvement of the COX-2 (rs2745557) polymorphism and its protein in PCa or BPH initiation and progression. Also, the coexistence of COX-2 (rs2745557) and obesity, smoking, or diabetes may lead to the development of PCa or BPH. PMID:26920155

  9. Epidermal growth factor-induced cyclooxygenase-2 enhances head and neck squamous cell carcinoma metastasis through fibronectin up-regulation

    PubMed Central

    Hsu, Jinn-Yuan; Chang, Kwang-Yu; Chen, Shang-Hung; Lee, Chung-Ta; Chang, Sheng-Tsung; Cheng, Hung-Chi; Chang, Wen-Chang; Chen, Ben-Kuen

    2015-01-01

    Epidermal growth factor receptor (EGFR) activation is a major cause of metastasis in many cancers, such as head and neck squamous cell carcinoma (HNSCC). However, whether the induction of cyclooxygenase-2 (COX-2) mediates EGF-enhanced HNSCC metastasis remains unclear. Interestingly, we found that EGF induced COX-2 expression mainly in HNSCC. The tumor cell transformation induced by EGF was repressed by COX-2 knockdown, and this repression was reversed by simultaneously treating the cells with EGF and prostaglandin E2 (PGE2). The down-regulation of COX-2 expression or inhibition of COX-2 activity significantly blocked EGF enhancement of cell migration and invasion, but the addition of PGE2 compensated for this inhibitory effect in COX-2-knockdown cells. COX-2 depletion inhibited EGF-induced matrix metalloproteinase (MMP)-1, MMP-2, MMP-3, MMP-9, and fibronectin expression and Rac1/cdc42 activation. The inhibitory effect of COX-2 depletion on MMPs and the fibronectin/Rac1/cdc42 axis were reversed by co-treatment with PGE2. Furthermore, depletion of fibronectin impeded the COX-2-enhanced binding of HNSCC cells to endothelial cells and tumor cells metastatic seeding of the lungs. These results demonstrate that EGF-induced COX-2 expression enhances HNSCC metastasis via activation of the fibronectin signaling pathway. The inhibition of COX-2 expression and activation may be a potential strategy for the treatment of EGFR-mediated HNSCC metastasis. PMID:25595899

  10. Quantitative Assessment of the Association of COX-2 (Cyclooxygenase-2) Immunoexpression with Prognosis in Human Osteosarcoma: A Meta-Analysis

    PubMed Central

    Xiao, Zengming; Wu, Hao; Wu, Yang

    2013-01-01

    Background Numerous studies examining the relationship between Cyclooxygenase-2 (COX-2) immunoexpression and clinical outcome in osteosarcoma patients have yielded inconclusive results. Methods We accordingly conducted a meta-analysis of 9 studies (442 patients) that evaluated the correlation between COX-2 immunoexpression and clinical prognosis (death). Pooled odds ratios (OR) and risk ratios (RR) with 95% confidence intervals (95% CI) were calculated using the random-effects or fixed-effects model. Results Meta–analysis showed no significant association between COX-2 positivity and age, gender, tumor location, histology, stage, metastasis or 90% necrosis. Conversely, COX-2 immunoexpression was associated with overall survival rate (RR=2.12; 95% CI: 1.10–3.74; P=0.009) and disease-free survival rate (RR=1.63; 95% CI: 1.17–2.28; P=0.004) at 2 years. Sensitivity analysis performed by omitting low quality studies showed that the pooled results were stable. Conclusions COX-2 positivity was associated with a lower 2-year overall survival rate and disease-free survival rate. COX-2 expression change is an independent prognostic factor in patients with osteosarcoma. PMID:24358237

  11. Inhibitors

    MedlinePlus

    ... Community Counts Blood Safety Inhibitors Articles & Key Findings Free Materials Videos Starting the Conversation Playing it Safe A Look at Hemophilia Joint Range of Motion My Story Links to Other Websites ...

  12. Enhanced cyclooxygenase-2 expression levels and metalloproteinase 2 and 9 activation by Hexachlorobenzene in human endometrial stromal cells.

    PubMed

    Chiappini, Florencia; Bastón, Juan Ignacio; Vaccarezza, Agustina; Singla, José Javier; Pontillo, Carolina; Miret, Noelia; Farina, Mariana; Meresman, Gabriela; Randi, Andrea

    2016-06-01

    Hexachlorobenzene (HCB) is an organochlorine pesticide that induces toxic reproductive effects in laboratory animals. It is a dioxin-like compound and a weak ligand of the aryl hydrocarbon receptor (AhR). Endometriosis is characterized by the presence of functional endometrial tissues outside the uterine cavity. Experimental studies indicate that exposure to organochlorines can interfere with both hormonal regulation and immune function to promote endometriosis. Altered expression of metalloproteinases (MMPs) in patients with endometriosis, suggests that MMPs may play a critical role. In the endometriotic lesions, prostaglandin E2 (PGE2) produced by cyclooxygenase-2 (COX-2), binds to its EP4 receptor (EP4), and via c-Src kinase induces MMPs activation, promoting endometriosis. We examined the HCB action on MMP-2 and MMP-9 activities and expression, COX-2 levels, PGE2 signaling, and the AhR involvement in HCB-induced effects. We have used different in vitro models: (1) human endometrial stromal cell line T-HESC, (2) primary cultures of Human Uterine Fibroblast (HUF), and (3) primary cultures of endometrial stromal cells from eutopic endometrium of control (CESC) and subjects with endometriosis (EESC). Our results show that HCB enhances MMP-2 and MMP-9 activities in T-HESC, HUF and ESC cells. The MMP-9 levels were elevated in all models, while the MMP-2 expression only increased in ESC cells. HCB enhanced COX-2 and EP4 expression, PGE2 secretion and the c-Src kinase activation in T-HESC. Besides, we observed that AhR is implicated in these HCB-induced effects. In conclusion, our results show that HCB exposure could contribute to endometriosis development, affecting inflammation and invasion parameters of human endometrial cells. PMID:27038655

  13. Effect of quercetin on metallothionein, nitric oxide synthases and cyclooxygenase-2 expression on experimental chronic cadmium nephrotoxicity in rats

    SciTech Connect

    Morales, Ana I.; Vicente-Sanchez, Cesar; Jerkic, Mirjana; Santiago, Jose M.; Sanchez-Gonzalez, Penelope D.; Perez-Barriocanal, Fernando; Lopez-Novoa, Jose M. . E-mail: jmlnovoa@usal.es

    2006-01-15

    Inflammation can play a key role in Cd-induced dysfunctions. Quercetin is a potent oxygen free radical scavenger and a metal chelator. Our aim was to study the effect of quercetin on Cd-induced kidney damage and metallothionein expression. The study was performed in Wistar rats that were administered during 9 weeks with either cadmium (1.2 mg Cd/kg/day, s.c.), quercetin (50 mg/kg/day, i.p.) or cadmium + quercetin. Renal toxicity was evaluated by measuring blood urea nitrogen concentration and urinary excretion of enzymes marker of tubular damage. Endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) renal expression were assessed by Western blot. Renal expression of metallothionein 1 and 2 (MT-1, MT-2) and eNOS mRNA was assessed by Northern blot. Our data demonstrated that Cd-induced renal toxicity was markedly reduced in rats that also received quercetin. MT-1 and MT-2 mRNA levels in kidney were substantially increased during treatment with Cd, being even higher when the animals received Cd and quercetin. Renal eNOS expression was significantly higher in rats receiving Cd and quercetin than in animals receiving Cd alone or in control rats. In the group that received Cd, COX-2 and iNOS expression was markedly higher than in control rats. In the group Cd + quercetin, no changes in COX-2 and iNOS expression were observed compared with the control group. Our results demonstrate that quercetin treatment prevents Cd-induced overexpression of iNOS and COX-2, and increases MT expression. These effects can explain the protection by quercetin of Cd-induced nephrotoxicity.

  14. Neuronal NOS and cyclooxygenase-2 contribute to DNA damage in a mouse model of Parkinson’s disease

    PubMed Central

    Hoang, Tuan; Choi, Dong-Kug; Nagai, Makiko; Wu, Du-Chu; Nagata, Tetsuya; Prou, Delphine; Wilson, Glenn L.; Vila, Miquel; Jackson-Lewis, Vernice; Dawson, Valina L.; Dawson, Ted M.; Chesselet, Marie-Françoise; Przedborski, Serge

    2013-01-01

    DNA damage is a proposed pathogenic factor in neurodegenerative disorders such as Parkinson’s disease. To probe the underpinning mechanism of such neuronal perturbation, we sought to produce an experimental model of DNA damage. We thus first assessed by in situ nick translation and emulsion autoradiography in the mouse brain the effect of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 4 × 20mg/kg, i.p., every 2 hours), a neurotoxin known to produce a model of Parkinson’s disease, on DNA. Here we show that DNA strand breaks occur in vivo in this mouse model of Parkinson’s disease with kinetics and a topography that parallel the degeneration of substantia nigra neurons, as assessed by FluoroJade-labeling. Previously, nitric oxide synthase (NOS) and cyclooxygenase-2 (Cox-2) were found to modulate MPTP-induced dopaminergic neuronal death. We thus assessed the contribution of these enzymes to DNA damage in mice lacking either neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), or Cox-2. We found that the lack of Cox-2 and of nNOS, but not of iNOS activity, attenuate MPTP-related DNA damage. We also found that not only nuclear, but mitochondrial DNA as well is a target for the MPTP insult. These results suggest that the loss of genomic integrity can be triggered by the concerted actions of nNOS and Cox-2, and provide further support to the view that DNA damage may contribute to the neurodegenerative process in PD. PMID:19616617

  15. An investigation of the rate of cyclooxygenase-2 expression on the surface of adenomatous and colorectal adenocarcinoma polyps

    PubMed Central

    Baghaei, Ramin; Beiraghdar, Mozhdeh; Sobhani, Ahmad; Rafei, Rahmatolah; Kolahi, Leila; Foladi, Lotfolah

    2015-01-01

    Background: Colorectal cancer (CRC) (adenomatous, adenocarcinoma) is one of the major causes of mortality and morbidity in human societies. Considering the importance of cyclooxygenase-2 (COX-2) expression in the incidence of CRC, in this study, the rate of COX-2 gene expression on polyps and CRCs were addressed. Materials and Methods: This is a cross-sectional descriptive analytic study carried out on the blocks of sampled tissue of adenomatous and colorectal adenocarcinoma polyps on 68 patients referred to Digestive Clinic in Isfahan Shariati Hospital in 2013. Patients were divided into two groups of polyps (n = 52) and cancer (n = 16). Given the presence of CRC or polyps by colonoscopy, samples were sent to the laboratory to measure the rate of COX-2 gene expression using immunohistochemistry. Results: In polyp group, 41 individuals (78.8%) had two or <2 polyps, 24 cases (46.2%) had a tubular polyp, and about a third of all patients had a big polyp. The most frequency of the polyp site was related to sigmoid with 19 cases (36.54%), in cancer group, it was related to the rectum with 9 cases (56.25%) that there was no significant difference between two groups (P < 0.05). The overall prevalence of COX-2 expression was positive in 51 cases (75%) and negative in 17 cases (25%). COX-2 gene expression was separately observed in 38 individuals (73.10%) in the polyp group and in 13 cases (81.25%) in the cancer group, and no significant difference was found (P > 0.05). Conclusion: There is no relationship between COX-2 gene expression and the surface of adenomatous and colorectal adenocarcinoma polyps. PMID:26601088

  16. Viscum album Exerts Anti-Inflammatory Effect by Selectively Inhibiting Cytokine-Induced Expression of Cyclooxygenase-2

    PubMed Central

    Hegde, Pushpa; Maddur, Mohan S.; Friboulet, Alain; Bayry, Jagadeesh; Kaveri, Srini V.

    2011-01-01

    Viscum album (VA) preparations are extensively used as complementary therapy in cancer and are shown to exert anti-tumor activities which involve the cytotoxic properties, induction of apoptosis, inhibition of angiogenesis and several other immunomodulatory mechanisms. In addition to their application in cancer therapy, VA preparations have also been successfully utilized in the treatment of several inflammatory pathologies. Owing to the intricate association of inflammation and cancer and in view of the fact that several anti-tumor phytotherapeutics also exert a potent anti-inflammatory effect, we hypothesized that VA exerts an anti-inflammatory effect that is responsible for its therapeutic benefit. Since, inflammatory cytokine-induced cyclo-oxygenase-2 (COX-2) and prostaglandin E2 (PGE2) play a critical role in the pathogenesis of inflammatory diseases, we investigated the anti-inflammatory effect of VA on regulation of cyclo-oxygenase expression and PGE2 biosynthesis by using human lung adenocarcinoma cells (A549 cells) as a model. A549 cells were stimulated with IL-1β and treated with VA preparation (VA Qu Spez) for 18 hours. PGE2 was analysed in the culture supernatants by enzyme immunoassay. Expression of COX-2 and COX-1 proteins was analyzed by immunoblotting and the expression of COX-2 mRNA was assessed by semi-quantitative RT-PCR. We found that VA Qu Spez inhibit the secretion of IL-1β-induced PGE2 in a dose-dependent manner. Further, we also show that this inhibitory action was associated with a reduced expression of COX-2 without modulating the COX-1 expression. Together these results demonstrate a novel anti-inflammatory mechanism of action of VA preparations wherein VA exerts an anti-inflammatory effect by inhibiting cytokine-induced PGE2 via selective inhibition of COX-2. PMID:22028854

  17. Cyclooxygenase-2 Expression as a Predictor of Para-Aortic Lymph Node Recurrence in Uterine Cervical Cancer

    SciTech Connect

    Kim, Jun-Sang Li Shengjin; Kim, Jin-Man; Yeo, Seung-Gu; Kim, Ki-Hwan; Cho, Moon-June

    2008-04-01

    Purpose: The overexpression of cyclooxygenase-2 (COX-2) is associated with a worse prognosis and the development of distant metastases in cervical cancer. This matched-pair analysis examined whether COX-2 expression is associated with para-aortic lymph node (PALN) recurrence in uterine cervical cancer treated with radiotherapy (RT). Methods and Materials: For this study, we matched 20 patients with PALN recurrence after definitive or postoperative RT by stage with 20 others who did not have PALN recurrence. Of the 20 patients with PALN recurrence, definitive or postoperative RT was performed in 11 and 9 patients, respectively. COX-2 expression was assessed immunohistochemically using a mouse monoclonal antibody on formalin-fixed paraffin-embedded tumor specimens taken before RT. A logistic regression model was used to predict for PALN recurrence. Results: COX-2 was expressed in 28 (70%) of the 40 patients. The staining intensity was as follows: weak in 19 (47%), moderate in 6 (15%), and strong in 3 (8%) patients. The patients with PALN recurrence had much greater expression of COX-2 (17 patients, 85%) than did the control group (11 patients, 55%; p = 0.04). Strong staining intensity of COX-2 was seen only in the PALN recurrence group. The statistically significant factors associated with PALN recurrence were positive pelvic lymph nodes (odds ratio, 7.61; 95% confidence interval, 1.55-37.37; p = 0.01) and COX-2 expression (odds ratio, 1.47; 95% confidence interval, 1.04-2.09; p = 0.03). Conclusion: Our findings suggest that COX-2 overexpression in the initial tumor tissue might be associated with PALN recurrence after RT in cervical cancer patients.

  18. Increased expression of nitric oxide synthase and cyclooxygenase-2 is associated with poor survival in cervical cancer treated with radiotherapy

    SciTech Connect

    Chen, Helen H.W.; Su, W.-C.; Chou, C.-Y.; Guo, H.-R.; Ho, S.-Y.; Que, Jenny; Lee, W.-Y. . E-mail: 7707@so-net.net.tw

    2005-11-15

    Purpose: To investigate the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in cervical cancer and their association with clinical outcome in patients treated with radical radiotherapy. Methods and Materials: One hundred sixty-seven consecutive patients with FIGO Stages IB-IVA squamous cell cervical cancer underwent radical radiotherapy, including external-beam radiotherapy or high-dose-rate brachytherapy, or both, between 1989 and 2002. Immunohistochemical studies of their formalin-fixed, paraffin-embedded tissues were performed. Univariate and multivariate analyses were performed to identify and evaluate the effects of the factors affecting patient survival. Results: Positive immunostainings of iNOS and COX-2 were observed in 58.7% and 64.1% of the participants, respectively. The expression of both iNOS and COX-2 was positively correlated (Spearman correlation coefficient = 0.49, p < 0.01), and their overexpression provided independent predictors of distant metastasis (odds ratio = 5.22 and 10.07, respectively; p < 0.01 for all). iNOS- and COX-2-expressing patients had significantly shorter disease-free survival (p < 0.01, both) and cause-specific overall survival (p = 0.01, p < 0.01, respectively). Patients with iNOS-positive/COX-2-positive tumors had the poorest survival rates. Coexpression of iNOS/COX-2, together with bulky tumor and advanced stage were independent prognostic factors for disease-free survival. Conclusion: Overexpression of iNOS or COX-2 or both was associated with decreased survival and a greater propensity to metastasize in cervical cancer patients treated with radiotherapy. Coexpression of iNOS and COX-2 may represent a useful biologic marker in patients receiving radical radiotherapy for cervical cancer.

  19. RhoA mediates cyclooxygenase-2 signaling to disrupt the formation of adherens junctions and increase cell motility.

    PubMed

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

    2006-12-15

    Cyclooxygenase-2 (COX-2) represents an important target for treatment and prevention of colorectal cancer. Although COX-2 signaling is implicated in promoting tumor cell growth and invasion, the molecular mechanisms that mediate these processes are largely unknown. In this study, we show that the RhoA pathway mediates COX-2 signaling to disrupt the formation of adherens junctions and increase cell motility. Disruption of adherens junctions promotes tumor cell invasion and metastasis and is often associated with tumor progression. We detected high levels of RhoA activity in HCA-7 colon carcinoma cells that constitutively express COX-2. Inhibition of COX-2 significantly reduced the levels of RhoA activity in HCA-7 cells, suggesting that constitutive expression of COX-2 stimulates RhoA activity. Interestingly, inhibition of COX-2 or silencing of COX-2 expression with small interfering RNA (siRNA) stimulated the formation of adherens junctions, concomitant with increased protein levels of E-cadherin and alpha-catenin. Furthermore, inhibition of RhoA or silencing of RhoA expression with siRNA increased the levels of E-cadherin and alpha-catenin. Inhibition of Rho kinases (ROCK), the RhoA effector proteins, also increased levels of E-cadherin and alpha-catenin and stimulated formation of adherens junctions. The motility of HCA-7 cells was significantly decreased when COX-2 or RhoA was inhibited. Therefore, our data reveal a novel molecular mechanism that links COX-2 signaling to disrupt the formation of adherens junctions; COX-2 stimulates the RhoA/ROCK pathway, which reduces levels of E-cadherin and alpha-catenin leading to disruption of adherens junction formation and increased motility. Understanding of COX-2 downstream signaling pathways that promote tumor progression is crucial for the development of novel therapeutic strategies. PMID:17178865

  20. Nitric oxide synthase, cyclooxygenase 2, and vascular endothelial growth factor in the angiogenesis of non-small cell lung carcinoma.

    PubMed

    Marrogi, A J; Travis, W D; Welsh, J A; Khan, M A; Rahim, H; Tazelaar, H; Pairolero, P; Trastek, V; Jett, J; Caporaso, N E; Liotta, L A; Harris, C C

    2000-12-01

    We have investigated the hypothesis that nitric oxide synthase (NOS2), cyclooxygenase-2 (COX2), and vascular endothelial growth factor (VEGF) protein levels individually demonstrate a direct correlation with microvessel density (MVD) and clinical outcome in human non-small cell lung cancer (NSCLC). Furthermore, we hypothesized that MVD may explain the propensity of certain histological lung cancer subtypes for early metastasis via a hematological route. Immunohistochemically, we studied the protein expression levels of NOS2, COX2, and VEGF and MVD by counting CD31-reactive blood vessels (BVs) in 106 surgically resected NSCLC specimens. NOS2, COX2, and VEGF immunoreactivity were observed in 48, 48, and 58%, respectively, of the study subjects, and their levels correlated with MVD at the tumor-stromal interphase (P < or = 0.001). More adenocarcindmas and large cell carcinomas displayed overexpression of NOS2 when compared with squamous cell carcinoma (SCC; r = 0.44; P < 0.001). NOS2 and COX2 levels were found to correlate positively with VEGF status (r = 0.44; P < 0.001, 0.01, and 0.03, respectively). These results attest to the significant interaction of these factors in the angiogenesis of NSCLC. Although neither angiogenic factors nor MVD correlated with patient survival, the latter correlated with tumor clinical stage in both squamous (SCC; 73 BVs/mm2) and non-SCC (78 BVs/mm2) tumors. These results indicate that angiogenesis is a complex process that involves multiple factors including NOS2, COX2, and VEGF. Furthermore, the role of angiogenesis in the biology of various histological lung cancer types may be different. The complexity of angiogenesis may explain the modest results observed in antiangiogenesis therapy that target a single protein. PMID:11156228

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

    PubMed

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

    2013-07-01

    Essential oils are concentrated hydrophobic liquids containing volatile aromatic compounds from plants. In the present study, the essential oil of Chamaecyparis obtusa (C. obtusa), which is commercially used in soap, toothpaste and cosmetics, was extracted. Essential oil extracted from C. obtusa contains several types of terpenes, which have been shown to have anti-oxidative and anti-inflammatory effects. In the present study, we examined the anti-inflammatory effects of C. obtusa essential oil in vivo and in vitro following the induction of inflammation by lipopolysaccharides (LPS) in rats. While LPS induced an inflammatory response through the production of prostaglandin E2 (PGE2) in the blood and peripheral blood mononuclear cells (PMNCs), these levels were reduced when essential oil was pre-administered. Additionally, the mechanism of action underlying the anti-inflammatory effects of C. obtusa essential oil was investigated by measuring the mRNA expression of inflammation‑associated genes. LPS treatment significantly induced the expression of transforming growth factor α (TNFα) and cyclooxygenase-2 (COX-2) in rats, while C. obtusa essential oil inhibited this effect. Taken together, our results demonstrate that C. obtusa essential oil exerts anti‑inflammatory effects by regulating the production of PGE2 and TNFα gene expression through the COX-2 pathway. These findings suggest that C. obtusa essential oil may constitute a novel source of anti-inflammatory drugs. PMID:23652412

  2. Expression of cyclooxygenase-2, peroxiredoxin I, peroxiredoxin 6 and nuclear factor-κB in oral squamous cell carcinoma

    PubMed Central

    LEE, EUN-YOUNG; KANG, JI-YEON; KIM, KYOUNG-WON

    2015-01-01

    Tumor development and progression are multistep processes that involve local tumor growth and invasion, followed by metastasis. The aggressiveness of the tumor is the major determinant of the mortality of oral cancer patients. The present study investigates whether the expression levels of cyclooxygenase-2 (COX-2), nuclear factor-κB (NF-κB), peroxiredoxin 1 (PRDX1) and PRDX6 are associated with the development, proliferation, differentiation and recurrence of oral squamous cell carcinoma (OSCC). The mRNA expression levels of COX-2, NF-κB, PRDX1 and PRDX6 were examined in 50 OSCC specimens and 19 normal oral mucosae by quantitative polymerase chain reaction (qPCR). qPCR analysis showed that the mRNA levels of COX-2 in OSCC were significantly higher than those in the normal oral mucosae (P=0.021). The expression levels of PRDX1 in high-stage tumors (T3 and T4) were significantly elevated compared with those in low-stage tumors (T1) (P=0.047). Additionally, the expression levels of NF-κB in the high-grade tumor were significantly elevated compared with those in the low-grade tumors (P=0.030). Overall, it was indicated that the expression of COX-2 is strongly associated with the development of OSCC. Moreover, the enhanced expression of PRDX1 and NF-κB may function in the progression of OSCC, which serves as a useful marker for prognosis in patients with oral cancer. PMID:26722300

  3. Effects of COX inhibitors on neurodegeneration and survival in mice exposed to the marine neurotoxin domoic acid.

    PubMed

    Ryan, James C; Cross, Cheryl A; Van Dolah, Frances M

    2011-01-01

    The marine neurotoxin domoic acid (DA) is a rigid analogue of the neurotransmitter glutamate and a potent agonist of kainate subtype glutamate receptors. Persistent activation of these receptor subtypes results in rapid excitotoxicity, calcium-dependent cell death, and neuronal degeneration in regions of the brain where glutamatergic pathways are concentrated. Previous work has shown that DA promotes the expression of inflammatory genes in the brain, such as cyclooxygenase 2 (COX2). To investigate the impact of inflammation on the development of neurodegeneration, and ultimately survival following DA administration, we used selective (L745337, Merck) and non-selective (acetylsalicylic acid (ASA)) COX inhibitors in DA exposed mice. Adult male ICR mice were given a regime of either ASA or L23547 both before and after a single LD50 dose of DA. Mice were observed immediately after toxin introduction and then sacrificed at 2 days post exposure. Our lower dose of L23547 increased survival and was most effective at decreasing neuronal degeneration in the CA1 and CA3 regions of the hippocampus, areas especially sensitive to DA excitotoxicity. This study shows that COX2 plays a role in DA induced neurodegeneration and death, and that inhibitors may be of value for treatment in human and wildlife DA exposure. PMID:20934488

  4. Yu Ping Feng San, an ancient Chinese herbal decoction, regulates the expression of inducible nitric oxide synthase and cyclooxygenase-2 and the activity of intestinal alkaline phosphatase in cultures.

    PubMed

    Du, Crystal Y Q; Choi, Roy C Y; Dong, Tina T X; Lau, David T W; Tsim, Karl W K

    2014-01-01

    Yu Ping Feng San (YPFS), a Chinese herbal decoction comprising Astragali Radix (AR; Huangqi), Atractylodis Macrocephalae Rhizoma (AMR; Baizhu), and Saposhnikoviae Radix (SR; Fangfeng), has been used clinically to treat inflammatory bowel diseases (IBD). Previously, we demonstrated a dual role of YPFS in regulating cytokine release in cultured macrophages. In this study, we elucidated the anti-inflammatory effect of YPFS that is mediated through modulating the expression of three key enzymes involved in IBD: inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and intestinal alkaline phosphatase (IALP). In a lipopolysaccharide (LPS)-induced chronic-inflammation model of cultured murine macrophages, YPFS treatment suppressed the activation of iNOS and COX-2 expression in a dose-dependent manner. Conversely, application of YPFS in cultured small intestinal enterocytes markedly induced the expression of IALP in a time-dependent manner, which might strengthen the intestinal detoxification system. A duality of YPFS in modulating the expression of iNOS and COX-2 was determined here. The expression of iNOS and COX-2 in macrophages was induced by YPFS, and this activation was partially blocked by the NF-κB-specific inhibitor BAY 11-7082, indicating a role of NF-κB signaling. These YPFS-induced changes in gene regulation strongly suggest that the anti-inflammatory effects of YPFS are mediated through the regulation of inflammatory enzymes. PMID:24967898

  5. An Asp49 Phospholipase A2 from Snake Venom Induces Cyclooxygenase-2 Expression and Prostaglandin E2 Production via Activation of NF-κB, p38MAPK, and PKC in Macrophages

    PubMed Central

    Lomonte, Bruno; Vinolo, Marco Aurélio Ramirez; Curi, Rui; Gutiérrez, José María; Teixeira, Catarina

    2014-01-01

    Phospholipases A2 (PLA2) are key enzymes for production of lipid mediators. We previously demonstrated that a snake venom sPLA2 named MT-III leads to prostaglandin (PG)E2 biosynthesis in macrophages by inducing the expression of cyclooxygenase-2 (COX-2). Herein, we explored the molecular mechanisms and signaling pathways leading to these MT-III-induced effects. Results demonstrated that MT-III induced activation of the transcription factor NF-κB in isolated macrophages. By using NF-κB selective inhibitors, the involvement of this factor in MT-III-induced COX-2 expression and PGE2 production was demonstrated. Moreover, MT-III-induced COX-2 protein expression and PGE2 release were attenuated by pretreatment of macrophages with SB202190, and Ly294002, and H-7-dihydro compounds, indicating the involvement of p38MAPK, PI3K, and PKC pathways, respectively. Consistent with this, MT-III triggered early phosphorylation of p38MAPK, PI3K, and PKC. Furthermore, SB202190, H-7-dihydro, but not Ly294002 treatment, abrogated activation of NF-κB induced by MT-III. Altogether, these results show for the first time that the induction of COX-2 protein expression and PGE2 release, which occur via NF-κB activation induced by the sPLA2-MT-III in macrophages, are modulated by p38MAPK and PKC, but not by PI3K signaling proteins. PMID:24808633

  6. Antioxidant and cyclooxygenase-2-inhibiting activity of 4,4'-biphenol, 2,2'-biphenol and phenol.

    PubMed

    Murakami, Yukio; Ishii, Hiroaki; Hoshina, Syuhei; Takada, Naoki; Ueki, Ayako; Tanaka, Shoji; Kadoma, Yoshinori; Ito, Shigeru; Machino, Mamoru; Fujisawa, Seiichiro

    2009-06-01

    The anthropogenic substance 4,4'-biphenol and its analogues are estrogenic and cytotoxic. It has been previously found that synthesized ortho-dimers of phenolic compounds possess potent antioxidative and anti-inflammatory activity. To clarify the relationships between radical-scavenging and anti-inflammatory activities, the radical-scavenging activities of 4,4'-biphenol, 2,2'-biphenol and phenol were investigated by using differential scanning calorimetry to measure the induction period for polymerization of methyl methacrylate initiated by thermal decomposition of 2,2'-azobisisobutyronitrile. We also investigated tThe inhibitory effects of these compounds on lipopolysaccharide (LPS)-stimulated cyclooxygenase-2 (COX-2) mRNA and protein expression and on binding of activator-protein-1 (AP-1) and nuclear factor kappa-B (NF-kappaB) to their respective consensus sequences were also investigated in RAW 264.7 cells. Furthermore, theoretical parameters such as phenolic-OH bond dissociation enthalpy (BDE) and ionization potential (IP(koopman)) were calculated at the density functional theory (DFT)/B3LYP levels. Cytotoxicity declined in the order 4,4'-biphenol > 2,2'-biphenol > phenol. 2,2'-Biphenol, but not 4,4'-biphenol, showed inhibitory effects on LPS-stimulated COX-2 expression and on AP-1 and NF-kappaB binding to their consensus sequences at 1-10 muM. Expression of COX-2 in RAW cells was enhanced by 4,4'-biphenol plus LPS, possibly because of radical-mediated transformation of 4,4'-biphenol to the cytotoxic diphenylquinone, as judged by the stoichiometric factor (n value) of 3.429 and low IP(koopman) value of this biphenol. In contrast, the anti-inflammatory activity of 2,2'-biphenol may be the result of the formation of a dimer derived from oxidation of this compound, as suggested by its n value close to 1. Phenol showed anti-inflammatory activity but did not completely inhibit COX-2 expression, even at higher concentrations. PMID:19528508

  7. Expression of integrin α3β1 and cyclooxygenase-2 (COX2) are positively correlated in human breast cancer

    PubMed Central

    2014-01-01

    Background Expression of integrin α3β1 is associated with tumor progression, metastasis, and poor prognosis in several cancers, including breast cancer. Moreover, preclinical studies have revealed important pro-tumorigenic and pro-metastatic functions for this integrin, including tumor growth, survival, invasion, and paracrine induction of angiogenesis. Our previously published work in a preclinical breast cancer model showed that integrin α3β1 promotes expression of cyclooxygenase-2 (COX2/PTGS2), a known driver of breast cancer progression. However, the clinical significance of this regulation was unknown. The objective of the current study was to assess the clinical relevance of the relationship between integrin α3β1 and COX2 by testing for their correlated expression among various forms of human breast cancer. Methods Immunohistochemistry was performed to assess co-expression of α3 and COX2 in specimens of human invasive ductal carcinoma (IDC), either on a commercial tissue microarray (n = 59 samples) or obtained from Albany Medical Center archives (n = 68 samples). Immunostaining intensity for the integrin α3 subunit or COX2 was scored, and Spearman’s rank correlation coefficient analysis was performed to assess their co-expression across and within different tumor subtypes or clinicopathologic criteria. Results Although expression of integrin α3 or COX2 varied among clinical IDC samples, a statistically significant, positive correlation was detected between α3 and COX2 in both tissue microarrays (rs = 0.49, p < 0.001, n = 59) and archived samples (rs = 0.59, p < 0.0001, n = 68). In both sample sets, this correlation was independent of hormone receptor status, histological grade, or disease stage. Conclusions COX2 and α3 are correlated in IDC independently of hormone receptor status or other clinicopathologic features, supporting the hypothesis that integrin α3β1 is a determinant of COX2 expression in human breast

  8. Secretory phospholipase A{sub 2} mediates progression of acute liver injury in the absence of sufficient cyclooxygenase-2

    SciTech Connect

    Bhave, Vishakha S.; Donthamsetty, Shashikiran; Latendresse, John R.; Muskhelishvili, Levan; Mehendale, Harihara M.

    2008-04-15

    Previous studies have shown that injury initiated by toxicants progresses even after most of the toxicant is eliminated from the body. One mechanism of progression of injury is the extracellular appearance of hydrolytic enzymes following leakage or upon cell lyses. Under normal conditions, after exposure to low to moderate doses of toxicants, secretory phospholipase A{sub 2} (sPLA{sub 2}) and other hydrolytic enzymes are known to appear in the extracellular spaces in order to cleanup the post-necrotic debris in tissues. We tested the hypothesis that sPLA{sub 2} contributes to progression of toxicant-initiated liver injury because of hydrolysis of membrane phospholipids of hepatocytes in the perinecrotic areas in the absence of sufficient cyclooxygenase-2 (COX-2). Male Sprague-Dawley rats were administered either a moderately hepatotoxic dose (MD, 2 ml CCl{sub 4}/kg, ip) or a highly hepatotoxic dose (HD, 3 ml CCl{sub 4}/kg, ip) of CCl{sub 4}. After MD, liver sPLA{sub 2} and COX-2 were co-localized in the necrotic and perinecrotic areas and their activities in plasma and liver increased before decreasing in tandem with liver injury (ALT and histopathology) leading to 100% survival. In contrast, after the HD, high extracellular and hepatic sPLA{sub 2} activities were accompanied by minimal COX-2 activity and localization in the liver throughout the time course. This led to progression of liver injury and 70% mortality. These data suggested a destructive role of sPLA{sub 2} in the absence of sufficient COX-2. Time- and dose-dependent destruction of hepatocytes by sPLA{sub 2} in isolated hepatocyte incubations confirmed the destructive ability of sPLA{sub 2} when present extracellularly, suggesting its ability to spread injury in vivo. These findings suggest that sPLA{sub 2}, secreted for cleanup of necrotic debris upon initiation of hepatic necrosis, requires the co-presence of sufficiently induced COX-2 activity to prevent the run-away destructive action of sPLA{sub 2

  9. Lactobacillus probiotic protects intestinal epithelium from radiation injury in a TLR-2/cyclo-oxygenase-2-dependent manner

    PubMed Central

    Ciorba, Matthew A; Riehl, Terrence E; Rao, M Suprada; Moon, Clara; Ee, Xueping; Nava, Gerardo M; Walker, Monica R; Marinshaw, Jeffrey M; Stappenbeck, Thaddeus S

    2011-01-01

    Background The small intestinal epithelium is highly sensitive to radiation and is a major site of injury during radiation therapy and environmental overexposure. Objective To examine probiotic bacteria as potential radioprotective agents in the intestine. Methods 8-week-old C57BL/6 wild-type or knockout mice were administered probiotic by gavage for 3 days before 12 Gy whole body radiation. The intestine was evaluated for cell-positional apoptosis (6 h) and crypt survival (84 h). Results Gavage of 5×107 Lactobacillus rhamnosus GG (LGG) improved crypt survival about twofold (p<0.01); the effect was observed when administered before, but not after, radiation. Conditioned medium (CM) from LGG improved crypt survival (1.95-fold, p<0.01), and both LGG and LGG-CM reduced epithelial apoptosis particularly at the crypt base (33% to 18%, p<0.01). LGG was detected in the distal ileal contents after the gavage cycle, but did not lead to a detectable shift in bacterial family composition. The reduction in epithelial apoptosis and improved crypt survival offered by LGG was lost in MyD88−/−, TLR-2−/− and cyclo-oxygenase-2−/− (COX-2) mice but not TLR-4−/− mice. LGG administration did not lead to increased jejunal COX-2 mRNA or prostaglandin E2 levels or a change in number of COX-2-expressing cells. However, a location shift was observed in constitutively COX-2-expressing cells of the lamina propria from the villi to a position near the crypt base (villi to crypt ratio 80:20 for control and 62:38 for LGG; p<0.001). Co-staining revealed these COX-2-expressing small intestinal lamina propria cells to be mesenchymal stem cells. Conclusions LGG or its CM reduce radiation-induced epithelial injury and improve crypt survival. A TLR-2/MyD88 signalling mechanism leading to repositioning of constitutive COX-2-expressing mesenchymal stem cells to the crypt base is invoked. PMID:22027478

  10. Cyclooxygenase-2 level and culture conditions influence NS398-induced apoptosis and caspase activation in lung cancer cells.

    PubMed

    Chang, H C; Weng, C F

    2001-01-01

    Cyclooxygenases (COXs) catalyze the synthesis of prostaglandins (PGs) from arachidonic acid. Overexpression of COX-2 is frequently found in human cancers and is suggested to play an important role in tumorigenesis. Recent studies indicated that COX-2 inhibitors exert potent anti-cancer effects on a number of cancers. Interestingly, some COX-2 inhibitors potently induce apoptosis, while other COX-2 inhibitors primarily induce growth inhibition. Therefore, there is a variability in the effects that different COX-2 inhibitors have on cancer cells. In this study, we demonstrated that induction of apoptosis of high COX-2-expressing A549 lung cancer cells by a specific COX-2 inhibitor NS398 was observed in cells cultured under serum-free condition. However, this drug induced G1 growth arrest rather than apoptosis in A549 cells maintained in 10% serum medium. Conversely, low COX-2-expressing H226 lung cancer cells were resistant to NS398-induced apoptosis under both serum-free and serum-containing conditions. Moreover, our results showed that NS398-induced apoptosis is associated with activation of caspase-3, a cysteine protease that plays a crucial role in the execution phase of apoptosis. These results suggest that the cytotoxic effect of COX-2 inhibitors on cancer cells may be influenced by extracellular environments and the anti-cancer action of these inhibitors in vivo needs careful evaluation. Additionally, a correlation between the level of COX-2 expression and the extent of apoptosis induced by COX-2 inhibitors was found. PMID:11605058