• Title, Summary, Keyword: COX-2

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SAR of COX-2 Inhibitors (COX-2 억제제의 구조-활성)

  • 권순경
    • Biomolecules & Therapeutics
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    • v.9 no.2
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    • pp.69-78
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    • 2001
  • Cyclooxygenase (COX) is an enzyme, which catalyzes the production of prostaglandins from arachi-donic acid and exists in two isoforms (COX-1 and COX-2). COX-1 is involved in the maintenance of physiological functions such as platelet aggregation, cytoprotection in the stomach and maintenance of normal kidney function. COX-2 is induced significantly in vivo under inflammatory conditions. COX-1 and COX-2 serve different physiological and pathological functions. All commercially available nonsteroidal antiinflammatory drugs (NSAIDS) are inhibitors of both COX-1 and COX-2. Therefore, selective inhibitors of COX-2 may be effective antiinflammatory agents without the ulcerogenic effects associated with current NSAms. Since the mid 1990s, a number of reports have been appeared on the preparation and biological activity of selective COX-2 inhibitors. Recently celecoxib, and rofecoxib, the representative COX-2 inhibitors, are introduced in the drug market. In this paper the relationship of structure-activity for selective COX-2 inhibitors is reviewed.

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Effects of Natural Extracts on COX-1 and COX-2 mRNA Expression on UVB-induced Skin Inflammation in C57BL/6 Mouse

  • Ahn, Ryoung-Me
    • Journal of Environmental Health Sciences
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    • v.32 no.6
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    • pp.566-570
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    • 2006
  • Exposure to ultraviolet B(UVB) radiation causes skin inflammation such as pigmentation and the induction of cyclooxygenase-2(COX-2) gene expression. In this study, we investigated the effect of natural extracts from Tea, EGb 761 and Korean red ginseng(KRG), on the pigmentation and expression of COX-1 and COX-2 mRNA in UVB-irradiated C57BL/6 mice. Before UVB irradiation, the skin color was significantly showed the lightening effect by topical application of natural compounds (p<.05). In the case of UVB irradiated mice, we observed a decrease in pigmentation by compounds (p<.05). In irradiated skin, COX-1 mRNA expression is not changed following UVB irradiation, but COX-2 gene increases. Also, natural compounds lowered mRNA levels of COX-2. Therefore, these results suggest that COX-2 mRNA increases by UVB irradiation. Also, Tea, EGb 761 and KRG as a topical application may inhibit skin pigmentation and modulate COX-2 mRNA level.

Effects of Cyclooxygenase-2 Expression on Lymphangiogenesis and Lymph Node Metastasis in Gastric Cancer Tissues (위암조직에 있어 COX-2 발현이 림프관신생과 림프절 전이에 미치는 영향)

  • Chun, Hu-An;Paik, Seung-Sam;Song, Young-Soo;Kwon, Sung-Joon
    • Journal of Gastric Cancer
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    • v.6 no.4
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    • pp.284-290
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    • 2006
  • Purpose: Many previous studies have suggested that cyclooxygenase-2 (COX-2) over expression is closely related to angiogenesis. However, few have reported the relationship between COX-2 and lymphangiogenesis which is still unclear, The aim of this study was to determine the relationship between COX-2 expression and lymphangiogenetic factor, VEGF-C, in human gastric cancer and to correlate COX-2 and VEGF-C expression with other clinocopathological features to investigate whether COX-2 contributes to lymphangiogenesis and enhances lymph node metastasis. Materials and Methods: One hundred patients who underwent curative radical surgery in Hanyang University hospital from July 1998 to June 2001 were selected. The expression of COX-2 and VEGF-C were detected by using immunohistochemistry, and the relationships between these two parameters and several clinicopathological factors (gender, stage, lymph node status, tumor location, Lauren classification and angioinvasion) were determined. Results: Increased COX-2 expression was found in 86 of 100 tumor samples (86%) and in 70 of 100 tumor samples (70%) with VEGF-C. A high correlation between VEGF-C expression and lymph node metastasis was observed (P=0.033) along as well as COX-2 expression (P=0.012). Also, there was a significant correlation between COX-2 and VEGF-C expression (P=0.026), yet no correlation were found between COX-2 and VEGF-C expression and other clinicopathological parameters. Conclusion: Our study suggests that COX-2 expression contributes to lymphangiogenesis by mediating VEGF-C and finally promoting lymph node metastasis.

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Cloning and Expression of the Cyclooxygenase-2 gene in the Rock bream, Oplegnathusfasciatus (돌돔, Oplegnathus fasciatus의 Cyclooxygenase-2 유전자의 cloning 및 발현분석)

  • Jin, Ji Woong;Kim, Do Hyung;Kim, Young Chul;Jeong, Hyun Do
    • Journal of fish pathology
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    • v.26 no.1
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    • pp.19-30
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    • 2013
  • Megalocytivirus is a major fish pathogen in marine aquaculture of Asian countries including Korea. Despite of many species affected by this pathogen, little is known interaction between megalocytivirus and the fish immune system. One of the cyclooxygenase isoforms, named COX-2, is playing an important role in immune regulation, and distinct from COX-1 isoform of constitutive activity. COX-2 enzyme is induced by various inflammatory signals, including injection of lipopolysaccharide or infection by pathogenic agents. We cloned COX-2 gene in rock bream using degenerated primers designed from reported sequences of other fish species in PCR followed with 5'- and 3'-end RACE-PCR. The full length of cDNA of rbCOX2 (rock bream COX-2) gene are 2655 bp and that translates into 609 amino acids. The rbCOX-2 genomic organization are found to span 10 exons separated by 9 introns. We also studied if the experimental infection of rock bream with megalocytivirus could affect the expression of COX-2 gene. When injected with LPS, expression of the COX-2 gene was reached peak level at 1 day post injection and showed 13.10 fold increased level compared with that of control. While, when injected with megalocytivirus, we were not able to find significantly increased COX-2 gene expression different from that of control. Cloned and analyzed COX-2 gene in rock bream will help to understand defence mechanisms in fish after viral infection and will also support the development of the measures for treatment and prevention of viral infection.

Prognostic Significance of Cyclooxygenase-2(COX-2) Expression in Primary, Resected Non-Small Cell Lung Cancer (원발성 비소세포폐암조직에서 Cyclooxygenase-2 발현의 예후인자로서의 의의)

  • Kim, Hak Ryul;Yang, Sei Hoon;Jeong, Eun Taik
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.2
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    • pp.169-177
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    • 2004
  • Background : Cyclooxygenase is the main target enzyme for the nonsteroidal anti inflammatory drugs (NSAIDs) that have been shown to suppress carcinogenesis in both experimental models and epidemiological studies. COX-2 plays an important role in solid tumor growth, invasiveness and angiogenesis, through, in part, the synthesis of prostaglandins, such as prostaglandin E2 (PGE2). In this study, the prognostic significance of an increase in COX-2 expression in lung cancer samples was evaluated. Material and Methods : The expression of COX-2, by immunohistochemistry, was studied in paraffin-embedded tumor blocks obtained from 84 patients(male 67, female 17, with a mean age of 63, ranging from 34 to 84 years) who had undergone surgery at Wonkwang University Hospital, between 1997 and 2002. For the evaluation of the relationships between COX-2 expression, and the clinical stage, metastasis to lymph nodes and survival, those cases showing the respective antigen expression in >10% of the tumor cells were considered positive. Result : Of the 84 patients, 61 (73%) exhibited more than 10% COX-2 immunoreactivities in the tumor and normal cells, whereas the remaining 23 showed no increase in the expression of COX-2. There was no significant relationship between the increased expression of COX-2 and the disease stage(p=0.1002) or cell type(p=0.152). The median survival was longer for the patients with a negative, compared to positive, COX-2 expression(36 compared to 24 months, p<0.05). The two year-survival rate was also higher in the patients with a negative COX-2 expression (78%) than those with a positive expression (47%, Kaplan-Meier, Log Rank, p < 0.05). Conclusion : The median survival was longer in the patients with a negative, compared to positive, COX-2 expression was longer than those with positive COX-2, having undergone complete resection due to primary non-small cell lung cancer.

Nitric Oxide Donor, NOR-3, Increased Expression of Cyclooxygenase-2, but not of Cyclooxygenase-1 in Cultured VSMC

  • Lee, Dong-Hyup;Park, Ji-Eun;Kang, Young-Jin;Lee, Kwang-Youn;Choi, Hyoung-Chul
    • The Korean Journal of Physiology and Pharmacology
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    • v.10 no.3
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    • pp.161-165
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    • 2006
  • NO and cyclooxygenase-2 (COX-2) are contributes to vascular inflammation induced by various stimulation. The mechanism, which explains a linkage between NO and COX-2, could be of importance in promoting pathophysiological conditions of vessel. We investigated the effects of NO donors on the COX-l and COX-2 mRNA/protein expression, as well as the nitrite production in culture medium of vascular smooth muscle cell (VSMC). VSMC was primarily cultured from thoracic aorta of rat. In this experiments, COX-l and COX-2 mRNA/protein expressions were analysed and nitrite productions were investigated using Griess reagent. VSMC did not express COX-2 protein in basal condition (Nonlipopolysaccharide (LPS) stimulated). In LPS-stimulated experiments, after 3 hours of NO donor pretreatment, LPS $10{\mu}g/ml$ was treated for 24 hours. COX-l protein expressions were unchanged by SNP and NOR-3. NOR-3 significantly increased COX-2 mRNA/protein expression under LPS stimulation. In contrast, SNP did not increase COX-2 mRNA/protein expression under LPS stimulation. Nitrite production was higher in NOR-3 treatment than SNP treatment under LPS stimulation. These results suggest that the expression of COX-2 in VSMC is regulated by NOR-3, COX-2 expressions were depending on the types of NO donor and LPS stimulation in VSMC.

The Effects of Cyclooxygenase-2(COX-2) Inhibitor on COX-2 and Prostaglandin E2 Expression in Ovalbumin Induced Early Phase Bronchoconstriction of Rats (Ovalbumin으로 유발된 백서의 즉시형 기관지 수축 반응에서 Cyclooxygenase-2(COX-2) 발현 양상 및 혈중 프로스타글란딘 E2 농도와 COX-2 억제제의 효과)

  • Lee, Sung-Yong;Lee, Sin-Hyung;Jung, Ki-Hwan;Kim, Byung-Gyu;Jung, Hae-Chul;Kim, Kyung-Kyu;Kwon, Young-Hwan;Kim, Ja-Hyeong;Lee, Ju-Han;Lee, Sang-Youb;Cho, Jae-Yoen;Shim, Jae-Joeng;In, Kwang-Ho;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.2
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    • pp.191-202
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    • 2000
  • Background: Bronchial asthma is characterized by airway hyperresponsiveness(BHR) and inflammation. The cyclooxygenase(COX) is believed to be one of the important enzymes in these inflammatory reactions. Recently, the COX was divided into two isoforms, COX1 and COX2. COX2 is induced by lipopolysaccharide and some cytokines at the inflammation site. Prostaglandin E2(PGE2), produced from COX2, may affect airway inflammation. The purpose of this study is to evaluate the effect of COX2 inhibitor on COX2 expression, plasma PGE2, airway resistance and histologic finding in an animal asthma model. Methods : Sprague-Dawley rats were divided into 3 groups. The normal control group did not receive any treatment, but the asthma control group was sensitized by ovalbumin but not treated with the COX2 inhibitor(nimesulide, Mesulid$^{(R)}$). The treatment group was sensitized and treated with nimesulide. Specific airway resistance(sRaw) before and after nimesulide ingestion was investigated. The PGE2 level in the plasma was examined and COX2 immunogold-silver stain on lung tissue was performed. Results: sRaw and eosionophilic infiltration on airway, which increased in the asthma control group, was compared to normal control(p=0.014). However, there was no difference in eosinophilic infiltration between asthma control and treatment groups(p=0.408) and no difference in COX2 expression on bronchiolar epithelium among the three groups. Plasma PGE2 levels were not statically different among the three groups. Conclusion: The role of COX2 in the allergen-induced BHR was not significant The effect of nimesulide was not observed on BHR, COX2 expression, and plasma PGE2 level. Therefore, COX2 may not be a major substance of allergic asthma.

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Posttranscriptional and posttranslational determinants of cyclooxygenase expression

  • Mbonye, Uri R.;Song, In-Seok
    • BMB Reports
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    • v.42 no.9
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    • pp.552-560
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    • 2009
  • Cyclooxygenases (COX-1 and COX-2) are ER-resident proteins that catalyze the committed step in prostanoid synthesis. COX-1 is constitutively expressed in many mammalian cells, whereas COX-2 is usually expressed inducibly and transiently. Abnormal expression of COX-2 has been implicated in the pathogenesis of chronic inflammation and various cancers; therefore, it is subject to tight and complex regulation. Differences in regulation of the COX enzymes at the posttranscriptional and posttranslational levels also contribute significantly to their distinct patterns of expression. Rapid degradation of COX-2 mRNA has been attributed to AU-rich elements (AREs) at its 3’UTR. Recently, microRNAs that can selectively repress COX-2 protein synthesis have been identified. The mature forms of these COX proteins are very similar in structure except that COX-2 has a unique 19-amino acid (19-aa) segment located near the C-terminus. This C-terminal 19-aa cassette plays an important role in mediation of the entry of COX-2 into the ER-associated degradation (ERAD) system, which transports ER proteins to the cytoplasm for degradation by the 26S proteasome. A second pathway for COX-2 protein degradation is initiated after the enzyme undergoes suicide inactivation following cyclooxygenase catalysis. Here, we discuss these molecular determinants of COX-2 expression in detail.

Cyclooxygenase-2 Expression in Invasive Breast Carcinomas of No Special Type and Correlation with Pathological Profiles Suggest a Role in Tumorigenesis Rather than Cancer Progression

  • Misron, Nurul Akmar;Looi, Lai-Meng;Mustapha, Nik Raihan Nik
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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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.

Comparative Study of Cyclioxygenase-2 Expression and HER-2/neu Amplification in Korean and Caucasian Women with Early-Onset Breast Carcinoma (한국인과 백인 젊은 여성 유방암 환자에서 Cyclooxygenase-2 발현과 HER-2/neu 증폭의 비교 연구)

  • Choi, Doo-Ho;Kim, Eun-Seog;Kim, Yong-Ho;Jin, So-Young;Lee, Dong-Wha;Haffty, Bruce G.
    • Radiation Oncology Journal
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    • v.22 no.4
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    • pp.307-315
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    • 2004
  • Purpose: The purpose of this work was to study the differences of cyclooxygenase (COX-2) expression between Korean and Caucasian patients with early-onset breast carcinoma by immunohistochemistry. The test were analyzed to find a correlation between COX-2 and other biomarkers including HER-2/neu amplification, because we previously reported that a significant difference had been found in the expression of HER-2/neu between the two races. Furthermore, we investigated prognostic significance of COX-2 in korean patients. Materials and Methods: Sixty Korean women who were diagnosed breast carcinoma at 45 years old or younger and 60 Caucasian women with breast carcinoma were selected for this study. The median age of both groups was 37 years and tumor sizes were distributed evenly between the two group. Paraffin embedded blocks of primary tumor were processed for immunohistochemical staining of COX-2. The COX-2 expression was evaluated according to the percentage of positive cells and the intensity of staining. And the results were compared with the data of the previous studies to find correlation between COX-2 and other parameters and survival data. Results: Proportion of the COX-2 expression in total patients was $27.6\%$. The percentage of tumors that stained positive for COX-2 in korean and Caucasian women with early-onset breast carcinoma were $37.9\%$ and $20.8\%$, respectively. The difference was statistically not significant(p=0.090). Expression of COX-2 was not associated with several clinicopathologic parameters including HER-2/neu overexpression, but negative estrogen receptor status was correlated with significance (p=0.046). The 5 year disease free survival rate for patients with COX-2 expression was $67.9\%$, compared to $81.9\%$ of the COX-2 negative patients and the result was statistically not significant. Conclusions : A significant difference was not found in the expression of COX-2 between the two groups of patients with early-onset breast carcinoma. And correlation between COX-2 and other parameters was not observed except estrogen receptor negativity. Large scaled further research including radiotherapy factors will be needed to identify COX-2 as a prognostic role in patients with early-onset breast carcinoma.