• Asian Pacific Journal of Cancer Prevention
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• 제16권4호
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• pp.1553-1558
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• 2015

Background: COX-2 has been shown to play an important role in the development of breast cancer and increased expression has been mooted as a poor prognostic factor. The purpose of this study was to investigate the relationship between COX-2 immunohistochemical expression and known predictive and prognostic factors in breast cancer in a routine diagnostic histopathology setting. Materials and Methods: Formalin-fixed paraffin-embedded tumour tissue of 144 no special type (NST) invasive breast carcinomas histologically diagnosed between January 2009 and December 2012 in Hospital Sultanah Bahiyah, Alor Setar, Kedah were immunostained with COX-2 antibody. COX-2 overexpression was analysed against demographic data, hormone receptor status, HER2-neu overexpression, histological grade, tumour size and lymph node status. Results: COX-2 was overexpressed in 108/144 (75%) tumours and was significantly more prevalent (87%) in hormone receptor-positive tumours. There was no correlation between COX-2 overexpression and HER2/neu status. Triple negative cancers had the lowest prevalence (46%) (p<0.05). A rising trend of COX-2 overexpression with increasing age was observed. There was a significant inverse relationship with tumour grade (p<0.05), prevalences being 94%, 83% and 66% in grades 1, 2 and 3 tumours, respectively. A higher prevalence of COX-2 overexpression in smaller size tumours was observed but this did not reach statistical significance. There was no relationship between COX-2 expression and lymph node status. Conclusions: This study did not support the generally held notion that COX-2 overexpression is linked to poor prognosis, rather supporting a role in tumorigenesis. Larger scale studies with outcome data and basic studies on cancer pathogenetic pathways will be required to cast further light on whether COX-2 inhibitors would have clinical utility in cancer prevention or blockage of cancer progression. In either setting, the pathological assessment for COX-2 overexpression in breast cancers would have an important role in the selection of cancer patients for personalized therapy with COX-2 inhibitors.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.245.1-245.1
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• 2003

As part of our research to discover novel synthetic flavonoids which can be applied to chronic inflammation diseases, many structurally modified flavone analogs have been synthesized to obtain information concerning the relationships between structures and the anti-inflammatory activities. We previously reported that 7-methoxyflavone analogs generally exhibited strong inhibitory activities against cyclooxygenase-2 catalyzed prostaglandin production. (omitted)

• The Korean Journal of Physiology
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• 제23권2호
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• pp.225-236
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• 1989

1) At the isolated perfused guinea-pig and rat heart heterometric autoregulation of the myocardium and myogenic autoregulation of the coronary vessels were induced by means of stepwise increases of perfusion pressure. 2) According to this loading test Frank-Starling function curves of the left ventricle and pressure-flow curves of the coronary vessels can be drawn. This graphic evaluation gives more information about the condition of the heart and the coronary vessels than simple evaluation under hemodynamic equilibrium. 3) There are significant differences in both curves between animal species and between different perfusate Mg concentration. 4) Myogenic autoregulation is not affected by the cyclooxygenase inhibitors indometacin and me- clofenamate. Thus it appears unlikely that prostanoides are involved in myogenic autoregulation. 5) Ca antagonists (Gallopamil, prenylamine) depress myogenic autoregulation dose-dependently. Enhanced myogenic autoregulation, induced by low extracellular magnesium, can be reduced effectively by Gallopamil. 6) Ginsenosides from Panax ginseng as well as the ginsenoside 'Rg' are effective inhibitors of myogenic autoregulation without major negative inotropic effects.

• The Korean Journal of Pain
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• 제24권4호
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• pp.179-184
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• 2011

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

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.355.3-356
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• 2002

Prostaglandins are synthesized by the enzyme cyclooxygenase (COX). Both constitutive (COX-1) and inducible (COX-2) isoforms have been identified. COX-2 expression is stimulated by inflammatory mediators such as growth factors and cytokines. Most non-steroidal anti-inflammatory drugs (NSAIDS) inhibit both isoforms of COX. Recent evidence suggests that selective inhibitors of COX-2 may possess diminished side effects reletive to common NSAIDS. Novel isothiazoles and isoxazoles were identified as selective inhibitiors of cycloxygenase-2(COX-2). (omitted)

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.114-121
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• 2023

선택적 cyclooxygenase (COX)-2 억제제는 기존의 비스테로이드성 소염제의 위장 부작용을 줄일 수 있는 새로운 대체제이다. 하지만, 최근 혈전을 일으켜 심혈관 질환의 위험을 증가시킨다는 보고가 있다. 따라서 본 연구에서는 유효성분인 ursolic acid를 각각 40, 50%로 극대화한 로즈마리 추출물(RE)의 항염증 효과와 이에 따른 심혈관 부작용의 안전성을 확인하였다. RE의 COX 효소 활성 저해 평가 결과 40, 50% RE는 100 ㎍/mL에서 양성 대조군인 celecoxib 및 rofecoxib와 비슷한 COX-2 저해 활성을 보였고, COX-1 저해 활성은 미미하였다. 이후 Lipopoly-saccharide (LPS)를 조건에 따라 처리한 RAW 264.7 세포에 40, 50% RE 1 ㎍/mL를 처리하여 COX-2, COX-1 유전자 발현, 세포 배양액의 prostaglandin E₂ (PGE₂), thromboxane B₂ (TXB₂) 농도를 확인하였다. 실험 결과 COX-2 유전자 발현은 40% RE가 LPS를 24시간 후처리한 조건에서 감소하였고, 40, 50% RE는 COX-1 유전자 발현 및 PGE₂, TXB₂ 농도에는 유의한 영향을 주지 않는 것으로 확인되었다. 따라서 RE는 혈전 생성에 관여하는 prostaglandins의 균형에 영향을 주지 않아 심혈관 혈전 생성의 위험성이 적을 것으로 사료된다.

• IMMUNE NETWORK
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• 제11권6호
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• pp.364-367
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• 2011

Background: Prostaglandins (PGs) play pathogenic and protective roles in inflammatory diseases. The novel concept of PGs as immune modulators is being documented by several investigators. By establishing an in vitro experimental model containing human follicular dendritic cell-like cells, HK cells, we reported that HK cells produce prostaglandin $E_2$ ($PGE_2$) and prostaglandin $I_2$ ($PGI_2$) and that these PGs regulate biological functions of T and B cells. Methods: To investigate the respective contribution of cyclooxygenase-1 (COX-1) and COX-2 to $PGE_2$ and $PGI_2$ production in HK cells, we performed siRNA technology to knock down COX enzymes and examined the effect on PG production. Results: Both $PGE_2$ and $PGI_2$ productions were almost completely inhibited by the depletion of COX-2. In contrast, COX-1 knockdown did not significantly affect PG production induced by lipopolysaccharide (LPS). Conclusion: The current results suggest that mPGES-1 and PGIS are coupled with COX-2 but not with COX-1 in human follicular dendritic cell (FDC) and may help understand the potential effects of selective COX inhibitors on the humoral immunity.

• BMB Reports
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• 제45권5호
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• pp.317-322
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• 2012

2-deoxy-D-glucose(2DG)-caused endoplasmic reticulum (ER) stress inhibits protein phosphorylation at tyrosine residues. However, the accurate regulatory mechanisms, which determine the inflammatory response of chondrocytes to ER stress via protein tyrosine phosphorylation, have not been systematically evaluated. Thus, in this study, we examined whether protein phosphorylation at tyrosine residues can modulate the expression and glycosylation of COX-2, which is reduced by 2DG-induced ER stress. We observed that protein tyrosine phosphatase (PTP) inhibitors, sodium orthovanadate (SOV), and phenylarsine oxide (PAO) significantly decreased expression of ER stress inducible proteins, glucose-regulated protein 94 (GRP94), and CCAAT/ enhancer-binding-protein- related gene (GADD153), which was induced by 2DG. In addition, we demonstrated that SOV and PAO noticeably restored the expression and glycosylation of COX-2 after treatment with 2DG. These results suggest that protein phosphorylation of tyrosine residues plays an important role in the regulation of expression and glycosylation during 2DG-induced ER stress in rabbit articular chondrocytes.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.86-86
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• 2001

Based on the potential inhibitors of cyclooxygenase-2 (COX-2) as anti-inflammatory or cancer chemopreventive agents, we have evaluated the active principles of COX-2 inhibition from natural products. The methanol extract of the cortex of Eugenia caryoplyllata (Myrtaceae) showed the potent inhibition of prostaglandin E$_2$(PGE$_2$) production in lipopolysaccharide (LPS)-activated RAW 264.7 cells (98.3% inhibition at the test concentration of 10 $\mu\textrm{g}$/$m\ell$) Further, hexane-soluble layer was the most active partition compared to ethyl acetate, n-butanol, and water -soluble parts. By bioassay-guided fractionation of hexane-soluble layer, eugenol was isolated and exhibited a significant suppression of PGE$_2$ production (IC$\_$50/=0.06$\mu\textrm{g}$/$m\ell$). In addition, eugenol suppressed the COX-2 gene expression in LPS-stimulated mouse macrop-hage cells. Therfore, eugenol might be a plausible lead candidate for further developing the COX-2 inhibitor as an anti-inflammatory or cancer chemopreventive agent.

• Archives of Pharmacal Research
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• 제28권1호
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• pp.1-15
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• 2005

Cancer is still a major global health concern even after an everlasting strive in conquering this dread disease. Emphasis is now given to chemoprevention to reduce the risk of cancer and also to improve the quality of life among cancer afflicted individuals. Recent progress in molecular biology of cancer has identified key components of the cellular signaling network, whose functional abnormality results in undesired alterations in cellular homeostasis, creating a cellular microenvironment that favors premalignant and malignant transformation. Multiple lines of evidence suggest an elevated expression of cyclooxygenase-2 (COX-2) is causally linked to cancer. In response to oxidative/pro-inflammatory stimuli, turning on unusual signaling arrays mediated through diverse classes of kinases and transcription factors results in aberrant expression of COX-2. Population-based as well as laboratory studies have explored a broad spectrum of chemopreventive agents including selective COX-2 inhibitors and a wide variety of anti-inflammatory phytochemicals, which have been shown to target cellular signaling molecules as underlying mechanisms of chemoprevention. Thus, unraveling signaling pathways regulating aberrant COX-2 expression and targeted blocking of one or more components of those signal cascades may be exploited in searching chemopreventive agents in the future.