• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.231-240
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• 2007

It has been reported the higher incidence rate of gastric cancer in our country. Helicobacter pylori (H. pylori), that exhibited a higher infection rate among Korean people, has been known as a cofactor to cause cancer. Therefore, the aim of this study was to identify correlations among overexpressions of COX-2 (Cyclooxygenase-2) gene, p53 mutation and cell proliferation index related to H. pylori. Taking 28 cases of gastric cancer with H. pylori detection, immunohistochemical staining for COX-2, p53 and Ki-67 were performed. In the H. pylori positive group, the well differentiated type and diffuse type of gastric cancer were distributed in larger area and the expression rate of COX-2 was revealed high. The H. pylori negative group showed higher p53 expression than that of the positive group. However, the statistical correlation between H. pylori and histopathological factors was not observed. The significantly higher expression of COX-2 had were observed in both well differentiated type and the intestinal type of gastric cancer. Although there were no statistical significances, this showed a higher inclination of manifest in the early gastric cancer. p53 exhibited a higher tendency of expression in the well differentiated, moderately differentiated and the intestinal type of gastric cancers including the early gastric cancer. Ki-67 was expressed in a significantly higher fashion along with the increase of age. In addition, it was significantly expressed in well differentiated type and intestinal type of gastric cancer. Therefore, these results suggest that H. pylori, COX-2, p53, and Ki-67 influences on the new occurrence of gastric cancer and its development procedures. In the future, the more researches would be required to focus on a larger category relative to gene expressions in gastric cancer.

• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.105-112
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• 2003

Selective COX (cyclooxygenase)-2 inhibitors including celecoxib have been shown to induce apoptosis and cell cycle changes in various tumor cells. New inhibitors are recently being developed as chemomodulating agents. We evaluated celecoxib and screened 150 synthetic compounds for anti-proliferative activities in vitro. Effects of celecoxib on COX activity, cell growth, cell cycle distribution, and apoptosis induction were determined in A549 COX-2 overexpressing human non-small cell lung cancer (NSCLC) cells. The COX inhibition of celecoxib increased with concentration up to 82% at $1\;{\mu}M$ after 24 hr exposure. Forty ${\mu}M$ and $50\;{\mu}M$ of ce1ecoxib induced $G_1$ arrest, and TUNEL-positive apoptotic cells, respectively. Among 150 compounds, several compounds were selected for having greater COX-2 inhibitory activity and higher selectivity than celecoxib with growth inhibitory activity. Celecoxib showed concentration-dependent COX inhibitory activity, and ability to induce cell cycle arrest and apoptosis in human NSCLC cells in vitro. Among synthetic analogues screened, several compounds showed promising in vitro activity as COX-2 inhibitory anticancer agents, which warrant further evaluation in vitro and in vivo.

• Journal of Korean Neurosurgical Society
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• v.38 no.4
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• pp.287-292
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• 2005

Objective : Kainic acid[KA] enhances the expression of nitric oxide synthase, increases nitric oxide[NO], and thus evokes epileptic convulsion, which results in neuronal damage in the rat brain. NO may stimulate cyclooxygenase type-2 [COX-2] activity, thus producing seizure and neuronal injury, but it has also been reported that KA-induced seizure and neurodegeneration are aggravated on decreasing the COX-2 level. This study was undertaken to investigate whether the suppression of NO using the NOS inhibitor, N-nitro-L-arginine methyl ester[L-NAME], suppresses or enhances the activity of COX-2. Methods : Silver impregnation and COX-2 immunohistochemical staining were used to localize related pathophysiological processes in the rat forebrain following KA-induced epileptic convulsion and L-NAME pretreatment. Post-injection survival of the rat was 1, 2, 3days and 2months, respectively. Results : After the systemic administration of KA in rats, neurodegeneration increased with time in the cornu ammonis [CA] 3, CA 1 and amygdala, as confirmed by silver impregnation. On pretreating L-NAME, KA-induced neuronal degeneration decreased. COX-2 enzyme activities increased after KA injection in the dentate gyrus, CA 3, CA 1, amygdala and pyriform cortex, as determined by COX-2 staining. L-NAME pretreatment prior to KA-injection, caused COX-2 activities to increase compared with KA- injection only group by 1day and 2days survival time point. Conclusion : These results suggest that L-NAME has a neuroprotective effect on KA-induced neuronal damage, especially during the early stage of neurodegeneration.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.345-356
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• 2004

The triclosan was shown to have anti-microbial and anti-inflammatory effect with inhibition of inflammatory mediators such as prostaglandin $E_2(PGE_2)$. The purpose of this study was to elucidate whether and how $PGE_2$ could be inhibited by triclosan in human gingival fibroblast. Human gingival fibroblast-1 cells (ATCC CRL2014) were pre-treated for 1 hour with triclosan (0.001 ${\mu}/ml{\sim}10$ ${\mu}/ml$) and then stimulated with $TNF-{\alpha}$ (1.0 ng/ml). $PGE_2$ synthesis was evaluated by ELISA and gene expression of COX-1 and COX-2 was evaluated by RT-PCR after $TNF-{\alpha}$, triclosan, and NS-398 (COX-2 inhibitor, 5, ${\mu}M$) and/ or cycloheximide (protein synthesis inhibitor, 2 ${\mu}g/ml$). Triclosan was cytotoxic to human gingival fibroblasts in the concentration higher than 1.0 ${\mu}g/ml$ for longer than 24 hours in tissue culture. The $PGE_2$ synthesis was inhibited by triclosan in dose-dependent manner. Greater COX-2 mRNA suppression was observed with triclosan (0.1 ${\mu}g/ml$) than with $TNF-{\alpha}$ alone, without change in COX-1 gene expression. Inhibitory effects of triclosan on $PGE_2$ synthesis disappeared in presence of cycloheximide. This study suggests that triclosan inhibit prostaglandin $E_2$ at the level of COX-2 gene regulation and require de novo protein synthesis.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.975-979
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• 2006

The extracts of Oenanthe javanica were evaluated for their effects on the expression of cyclooxygenase-2 (COX-2), which is mediated by the translocation of the p65 subunit into the nucleus. Fractions of ethyl acetate and chloroform from 80% ethanol extracts of O. javanica exhibited inhibitory effects on the secretion of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) from lipopolysaccharide (LPS)-stimulated peritoneal macrophages; however, the aqueous- and hexane-fractions showed no significant effect. The ethyl acetate- and chloroform-fractions also reduced the COX-2 enzyme levels after 24-hr treatment. RT-PCR showed that the mRNA levels of COX-2 decreased following treatment with these fractions, suggesting that COX-2 expression is transcriptionally regulated by these extracts. We examined the effects of the chloroform- and ethyl acetate-fractions on the cytosolic activation of nuclear factor-${\kappa}B$ ($NF-{\kappa}B$, p65 subunit) and on the degradation of inhibitor-${\kappa}B{\alpha}$ ($I-{\kappa}B{\alpha}$) in order to determine the mechanism of COX-2 regulation. The LPS-stimulated activation of the p65 subunit was significantly blocked upon the addition of $50\;{\mu}g/mL$ of these fractions, and the cytosolic $I-{\kappa}B{\alpha}$ degradation process was simultaneously inhibited. These findings suggest that the inhibition of COX-2 expression by the ethyl acetate-and chloroform-fractions may result from the inhibition of p65 translocation by blocking the degradation of $I-{\kappa}B{\alpha}$; this may be the mechanistic basis for the anti-inflammatory effects of O. javanica.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4539-4543
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• 2013

Background: Transitional cell carcinoma (TCC) is the most predominant type of urinary bladder tumor. As cyclooxygenase (COX)-2 is recently introduced as an attractive target molecule in bladder TCC, we evaluated the immunohistochemical expression of this marker and its association with several clinicopathological characteristics. Materials and Methods: This cross-sectional study was performed in the Pathology department of Sina Hospital in Tehran, Iran during 2006-2011. Ninety-two paraffin embedded blocks were selected from patients with urinary bladder TCC who underwent cystectomy or transurethral resection (TUR). Then, we assessed COX-2 expression by immunohistochemical staining using antibody against COX-2. Staining in more than 5% of tumor cells was considered as positive expression. Results: COX-2 was expressed in 50 % of our patients. This marker was markedly expressed in high grade bladder TCC (62.1%) versus other grades and there was statistically a significant difference in COX-2 expression between various grades (p=0.008). In addition, patients' age, lymphatic and perineurial invasion were associated with the expression of COX-2 (p=0.001, 0.015 and 0.039, respectively). However, other parameters such as stage, tumor size, venous invasion and lymph node metastasis did not show any significant relationship with this marker (all, p>0.05). Conclusions: COX-2 was expressed in urinary bladder TCC especially in high grade forms, advocating its probable role in the differentiation of this tumor. Accordingly, COX-2 could be a valuable biological target molecule in the evaluation and treatment of patients with bladder TCC.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.558-566
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• 1998

Two isoforms of cyclooxygenase (COX) have been identified - COX-1, which is constitlitively expressed in most tissues, and the inducible form, COX-2, of which expression is induced by inflammatory signals and mitogens. It has been considered that the beneficial effects of NSAIDs are due to the inhibition of COX-2 activity and the side effects are from the inhibition of COX-1 activity. Therefore, it is essential to develop selective COX-2 inhibitor for developing new GI-tolerable NSAIDS. To discover new leads for developing selective COX-2 inhibitors, three-hundred extracts of natural products were primarily screened with the system of prostaglandin accumulation in LPS-stimulated mouse peritoneal macrophages. To identify whether these inhibitory activities of crude extracts on the accumulation of Prostaglandins were derived from direct action against COX-2, the effects of selected extracts on exogenous arachidonic acid-derived production of prostaglandins by LPS-stimulated macrophages were determined. Among them, 5 methanol extracts of natural products, such as Zingiberis Rhizoma, Alpinae Officinarum Rhizoma, Caryophilli Flos, Scutellariae Radix, Dalbergia ordorifera. inhibited more than 70% of the prostaglandin production in LPS-stimulated mouse peritoneal macrophages at a con-centration of 1${\mu}$g/ml.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.383-388
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• 2003

Bee venom is used as a traditional medicine for treatment of arthritis. The anti-inflammatory activity of the n-hexane, ethyl acetate, and aqueous partitions from bee venom (Apis mellifera) was studied using cyclooxygenase (COX) activity and pro-inflammatory cytokines (TNF-$\alpha and IL-1\beta$) production, in vitro. COX-2 is involved in the production of prostaglandins that mediate pain and support the inflammatory process. The aqueous partition of bee venom showed strong dose-dependent inhibitory effects on COX-2 activity ($IC_{50} = 13.1 \mu$ g/mL), but did not inhibit COX-1 activity. The aqueous partition was subfractionated into three parts by molecular weight differences, namely, B-F1 (above 20 KDa), B-F2 (between 10 KDa and 20 KDa) and BF-3 (below 10 KDa). B-F2 and B-F3 strongly inhibited COX-2 activity and COX-2 mRNA expression in a dose-dependent manner, without revealing cytotoxic effects. TNF-$\alpha and IL-1\beta$ are potent pro-inflammatory cytokines and are early indicators of the inflammatory process. We also investigated the effects of three subfractions on TNF-$\alpha and IL-1\beta$ production using ELISA method. All three subfractions, B-F1, B-F2 and B-F3, inhibited TNF-$\alpha and IL-1\beta$production. These results suggest the pharmacological activities of bee venom on anti-inflammatory process include the inhibition of COX-2 expression and the blocking of pro-inflammatory cytokines (TNF-$\alpha and IL-1\beta$) production.

• Tuberculosis and Respiratory Diseases
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• v.86 no.4
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• pp.304-318
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• 2023

Background: Cancer-associated fibroblasts (CAFs) are key components of the tumor microenvironment and significantly contribute to immune evasion. We investigated the effects of CAFs on the immune function of CD4+ and CD8+ T cells in non-small cell lung cancer (NSCLC). Methods: We isolated CAFs and normal fibroblasts (NFs) from tumors and normal lung tissues of NSCLC patients, respectively. CAFs were co-cultured with activated T cells to evaluate their immune regulatory function. We investigated the effect of CAF conditioned medium (CAF-CM) on the cytotoxicity of T cells. CAFs were also co-cultured with activated peripheral blood mononuclear cells and further incubated with cyclooxygenase-2 (COX2) inhibitors to investigate the potential role of COX2 in immune evasion. Results: CAFs and NFs were isolated from the lung tissues (n=8) and lymph nodes (n=3) of NSCLC patients. Immune suppressive markers, such as COX2 and programmed death-ligand 1 (PD-L1), were increased in CAFs after co-culture with activated T cells. Interestingly, CAFs promoted the expression of programmed death-1 in CD4+ and CD8+ T cells, and strongly inhibited T cell proliferation in allogenic and autologous pairs of CAFs and T cells. CAF-CM decreased the cytotoxicity of T cells. COX2 inhibitors partially restored the proliferation of CD4+ and CD8+ T cells, and downregulated the expression of COX2, prostaglandin E synthase, prostaglandin E2, and PD-L1 in CAFs. Conclusion: CAFs promote immune evasion by suppressing the function of CD4+ and CD8+ T cells via their effects on COX2 and PD-L1 in NSCLC. The immunosuppressive function of CAFs could be alleviated by COX2 inhibitors.

• Communications for Statistical Applications and Methods
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• v.14 no.1
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• pp.141-146
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• 2007

In this paper, we consider a Box-Cox transformed threshold GARCH(1,1) process and find a sufficient condition under which the process is geometrically ergodic and has the ${\beta}$-mixing property with an exponential decay rate.