• Title, Summary, Keyword: COX-2

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Inhibitory effect of Astragali Radix on COX-2 activity (황기의 COX-2 활성 억제 효과)

  • Kim, Eun-Jeong;Oh, O-Jin;Lee, Sang-Kook;Yang, Ki-Sook
    • Korean Journal of Pharmacognosy
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    • v.32 no.4
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    • pp.311-315
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    • 2001
  • The root of Astragalus membranaceus Bunge (Leguminosae), which has been used for the treatment of hypertension, chronic hepatitis, duodenal ulcers, chronic nephritis and promotion of immunity in folk remedies. Cyclooxygenase (COX-2) is responsible for the production of large amounts of proinflammatory prostaglandins (PGs) at the inflammatory site. Thus, a logical approach to the treatment of inflammatory disease should involve the inhibitors of COX-2. To develop new COX-2 inhibitors from natural products, Astragali Radix was screened by inhibiting prostaglandin $E_2(PGE_2)$ generation in the culture medium using enzyme immunometric assay. Two isoflavone glycosides, $7,2'-dihydroxy-3',4'-dimethoxyisoflavan-7-O-{\beta}-D-glucoside$ and $calycosin-7-O-{\beta}-D-glucoside$ isolated from Astragali Radix inhibited COX-2 activity.

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Potentiation of COX-2 Induction by C2-ceramide, a Potential Cell Death Marker

  • Kim, Sang-Geon
    • Proceedings of the Korean Society of Toxicology Conference
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    • pp.13-14
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    • 2003
  • Ceramide, a potential cell death marker formed by sphingomyelinase, is involved in the expression of cyclooxygenase-2 (COX-2). This study examines the effect of C2-ceramide (C2), a cell-permeable ceramide analog, on the LPS-inducible COX-2 expression and signaling pathways. C2 did not induce COX-2, but potentiated LPS-inducible COX-2 expression in Raw264.7 cells, whereas dihydro-C2 was inactive.(omitted)

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Expression of Cyclooxygenase-2 (COX-2) in Colorectal Adenocarcinoma: an Immunohistochemical and Histopathological Study

  • Mahmoud, Abla Sayed;Umair, Ayesha;Azzeghaiby, Saleh Nasser;Alqahtani, Fahad Hussain;Hanouneh, Salah;Tarakji, Bassel
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6787-6790
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    • 2014
  • Background: The aim of this study was to evaluate cyclooxygenase-2 (COX-2) immunoreactivity in colorectal adenocarcinomas and to find correlations with different pathological features. Materials and Methods: This study included 35 cases of colorectal carcinoma foir which surgical colectomy specimens were collected. Immunohistochemical staining of COX-2 (cyclooxygenase-2) is done by using the Streptavidin-biotin technique. Results: This work reveals that COX-2 is positive in most cases of colorectal carcinoma and negative in normal colon tissue with statistically non significant relations between COX-2 immunostaining and different pathological features. Conclusions: Our data suggest over expression of COX-2 protein in colorectal carcinoma in contrast to normal mucosa, with a possible role in cell proliferation in carcinogenesis.

Impact of Cyclooxygenase-2 Expression on the Survival of Glioblastoma (다형성아교모세포종 환자에서 Cyclooxygenase-2 발현이 생존율에 미치는 영향)

  • Choi, Young-Min;Kim, Dae-Cheol;Kim, Ki-Uk;Song, Young-Jin;Lee, Hyung-Sik;Hur, Won-Joo;Choi, Sun-Seob;Seo, Su-Yeong
    • Radiation Oncology Journal
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    • v.25 no.3
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    • pp.145-150
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    • 2007
  • Purpose: To investigate the degree and effect of cyclooxygenase (COX)-2 expression on the survival of patients with glioblastoma multiforme (GM). Materials and Methods: Between 1997 and 2006, thirty consecutive GM patients treated with surgery and postoperative radiotherapy (dose range: $44{\sim}65.1$ Gy, median dose: 61.2 Gy) were included in the study. Three patients were excluded that discontinued radiotherapy before receiving a dose of 40 Gy due to mental deterioration. The expression of the COX-2 protein in surgical specimens was examined by immunohistochemical analysis. Survival analysis and verification were performed with respect to sex, age, performance status, resection extent, radiotherapy dose, and degree of COX-2 expression using the Kaplan-Meier method and the log rank test. Results: The median length of follow-up was 13.3 months (range:$6{\sim}83$ months). Staining for COX-2 was positive in all patient samples. Staining for COX-2 that was positive for over 75% of the tumor cells was found in 24 patients. Staining for COX-2 that was positive in less than 25% of tumor cells was found in 3 patients (10.0%), staining for COX-2 that was positive in 25 to 50% of tumor cells was found in 1 patient (3.3%), staining for COX-2 that was positive in 50 to 75% of tumor cells was found in 2 patients (6.7%) and staining for COX-2 that was positive in 75 to 100% of tumor cells was found in 24 patients (80.0%). The median survival and two-year survival rate were 13.5 months and 17.5%, respectively. The survival rate was influenced significantly by the degree of resection (tumor removal by 50% or more) and radiotherapy dose (59 Gy or greater) (p<0.05). The median survival of patients with staining for COX-2 that was positive in less than 75% of tumor cells and in at least 75% of tumor cells was 15.5 and 13.0 months, respectively (p>0.05), and the two-year survival for these groups was 33.3 and 13.3%, respectively (p>0.05). Conclusion: The absence of a statistical correlation between the degree of COX-2 expression and survival in GM patients, despite the high rate of COX-2 positive tumor cells in the GM patient samples, requires further studies with a larger series to ascertain the prognostic value of the degree of COX-2 expression in GM patients.

Docking Mode of 4,5-Diarylpyrroles into Cyclooxygenase-1 and Cyclooxygenase-2 (Cyclooxygenase-1과 Cyclooxygenase-2에 대한 4,5-Diarylpyrroles의 Docking Mode)

  • 이종달;도성탁;구본기
    • YAKHAK HOEJI
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    • v.43 no.6
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    • pp.776-781
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    • 1999
  • Dockings of 4,5-diarylpyrroles into cyclooxygenase-1 and cyclooxygenase-2 were carried out by GOLD program. The sulfonyl groups bonded to 5-phenyl ring of 4,5-diarylpyrroles are directed to Arg513 of COX-2 and Tyr385 of COX-2 docking modes of pyrroles are different from COX-1. Tyr385 and Arg120 of COX-1 and COX-2 have been recognized as important residues. Val523 of COX-2 may be also important. A new COX-2 selective inhibitors could be designed from the docking study.

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Synthesis and COX-2 Inhibitory Activity of Benzothiazine-3-carboxamide Derivatives (Benzothiazine-3-carboxamide 유도체의 합성과 COX-2 저해효과)

  • 신혜순;최희전;권순경
    • YAKHAK HOEJI
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    • v.46 no.6
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    • pp.375-380
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    • 2002
  • In this study, newly designed COX-2 inhibitors, synthetic derivatives of benzothiazine-3-carboxamide, were screened in vitro for selectivity of COX-1 and COX-2 inhibition properties. 7-Bromo-1,2-benzoisothiazine derivatives were obtained from 4-bromotoluene over the chlorosulfonation, amination and oxidation. And benzothiazine ring was synthesized through Gabriel-Colmann rearrangement reaction. To evaluate inhibitory effect of COX-2, synthetic derivatives of benzothiazine-3-carboxamide were tested with accumulation of prostaglandin by lipopolysaccharide in aspirin-treated murine macropharge cell. Some of the synthesized lead compounds have potentially shown the structure-activity relationship for selectivity of COX-2 inhibition activity.

Silencing of COX-2 by RNAi Modulates Epithelial-Mesenchymal Transition in Breast Cancer Cells Partially Dependent on the PGE2 Cascade

  • Cao, Juan;Yang, Xiao;Li, Wen-Tong;Zhao, Chun-Ling;Lv, Shi-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9967-9972
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    • 2014
  • In order to prove whether downregulation of COX-2 (Cyclooxygenase-2) could modulate the epithelial-mesenchymal transition (EMT) of breast cancer, celecoxib and siRNA were respectively used to inhibit COX-2 function and expression in MDA-MB-231 cells. The EMT reversal effect in the RNAi treated group was better than that of the celecoxib group while there were no obvious differences in the medium $PGE_2$ levels between the two groups. The results show that COX-2 pathways may contribute considerably to EMT of breast cancer cells, partially dependent on the PGE2 cascade. Akt2, ZEB2 and Snail were measured to clarify the underlying mechanisms of COX-2 on EMT; COX-2 may modulate EMT of breast cancer by regulating these factors. This finding may be helpful to elucidate the mechanisms of selective COX-2 inhibitor action in EMT modulation in breast cancer.

NDRG2 Controls COX-2/PGE2-Mediated Breast Cancer Cell Migration and Invasion

  • Kim, Myung-Jin;Kim, Hak-Su;Lee, Soo-Hwan;Yang, Young;Lee, Myeong-Sok;Lim, Jong-Seok
    • Molecules and Cells
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    • v.37 no.10
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    • pp.759-765
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    • 2014
  • N-myc downstream-regulated gene 2 (NDRG2), which is known to have tumor suppressor functions, is frequently down-regulated in breast cancers and potentially involved in preventing the migration and invasion of malignant tumor cells. In the present study, we examined the inhibitory effects of NDRG2 overexpression, specifically focusing on the role of cyclooxygenase-2 (COX-2) in the migration of breast cancer cells. NDRG2 overexpression in MDA-MB-231 cells inhibited the expression of the COX-2 mRNA and protein, the transcriptional activity of COX-2, and prostaglandin $E_2$ ($PGE_2$) production, which were induced by a treatment with phorbol-12-myristate-13-acetate (PMA). Nuclear transcription factor-${\kappa}B$ (NF-${\kappa}B$) signaling attenuated by NDRG2 expression resulted in a decrease in PMA-induced COX-2 expression. Interestingly, the inhibition of COX-2 strongly suppressed PMA-stimulated migration and invasion in MDA-MB-231-NDRG2 cells. Moreover, siRNA-mediated knockdown of NDRG2 in MCF7 cells increased the COX-2 mRNA and protein expression levels and the PMA-induced COX-2 expression levels. Consistent with these results, the migration and invasion of MCF7 cells treated with NDRG2 siRNA were significantly enhanced following treatment with PMA. Taken together, our data show that the inhibition of NF-${\kappa}B$ signaling by NDRG2 expression is able to suppress cell migration and invasion through the down-regulation of COX-2 expression.

Production of Prostaglandin $E_2$ and $I_2$ is Coupled with Cyclooxygenase-2 in Human Follicular Dendritic Cells

  • Cho, Wha-Jung;Kim, Jin-I;Cho, Kyu-Bong;Choe, Jong-Seon
    • IMMUNE NETWORK
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    • v.11 no.6
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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.

Expression of Arachidonate-Preferring Acyl-CoA Synthetase 4 in the Mouse Uterus during Pregnancy (임신 중인 생쥐 자궁에 있어서 아라키돈산에 특이적인 Acyl-CoA Synthetase 4의 발현)

  • 이상미;박효영;정영희;문승주;강만종
    • Reproductive and Developmental Biology
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    • v.28 no.2
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    • pp.89-94
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    • 2004
  • This study was conducted to determine expression of acyl-CoA synthetase 4(ACS4), which is involved in converts arachidonic acid to postaglandins, in the mouse uterus during pregnancy. In arachidonic acid metabolism, acyl-CoA synthetase plays a key role in the esterification of free arachidonic acid into membrane phospholipids. Following its release by the action of calcium dependent phospholipases, free arachidonic acid is believed to be rapidly converted to arachidonoyl-CoA and reesterified into phospholipids in order to prevent excessive synthesis of prostaglandins. Here we demonstrate that ACS4 gene are differentially regulated in the peri-implatation mouse uterus. During the preimplantation period(days 0.5∼3.5), the ACS4 gene was expressed in the uterus until day 3.5 after which the expression was downregulated. The expression of cPLA2, COX1, and COX2 gene was similar to that of ACS4 gene in the preimplantation periods. However expression levels of COX1 gene show much variation on the various days of pregnancy examined. These data, suggest that ACS4 expression in preimplantation period is involved in initial attachment reaction with cPLA2, COX1, and COX2 gene.