Therapeutic effect and mechanism of Xiaoyao Kangai Jieyu Recipe on mice with breast cancer related depression through regulating COX pathway / 中国中药杂志

This study aimed to investigate the intervention effect and mechanism of Xiaoyao Kangai Jieyu Recipe(XKJR) on hip-pocampal microglia and neuronal damage in mice with breast cancer related depression. The mouse model of breast cancer related depression was established by inoculation of 4T1 breast cancer cells in axilla and subcutaneous injection of corticosterone(30 mg·kg~(-1)). The successfully modeled mice were randomly divided into a model group, a positive drug group(capecitabine 60 mg·kg~(-1)+fluoxetine 19.5 mg·kg~(-1)), and XKJR group(19.5 mg·kg~(-1) crude drug), with 6 in each group. Another 6 normal mice were taken as a normal group. The administration groups were given corresponding drugs by gavage, while the normal and model groups were given an equal volume of distilled water, once a day for 21 consecutive days. The depressive behavior of mice was assessed by glucose consumption test, open field test and novelty-suppressed feeding test. Hematoxylin and eosin(HE) staining and tumor suppression rate were used to evaluate the changes of axillary tumors. The mRNA expressions and the relative protein expressions of interleukin-1β(IL-1β), interleukin-18(IL-18), cyclooxyganese-2(COX-2) and glutamyl-prolyl-tRNA synthetase(EPRs) in the hippocampus of mice were determined by quantitative real-time polymerase chain reaction(qRT-PCR) and immunohistochemistry, respectively. Immunofluorescence was performed to detect the mean fluorescence intensity of CD11b, a marker of hippocampal microglia activation. Nissler staining and transmission electron microscopy were employed to observe the morphological changes and the ultramorphological changes of hippocampal neurons, respectively. The experimental results indicated that compared with the normal group, the model group had reduced glucose consumption and lowered number of total activities in open field test(P<0.05, P<0.01), prolonged first feeding latency in no-velty-suppressed feeding test(P<0.01), and significant depression-like behavior; the contents of IL-1β, IL-18, COX-2, and EPRs in hippocampus were increased(P<0.05, P<0.01), with hippocampal microglia activation and obvious neuronal damage. Compared with the model group, the positive drug group and the XKJR group presented an improvement in depressive behaviors, a decrease in the contents of IL-1β, IL-18, COX-2 and EPRs in hippocampus, and an alleviation in the activation of hippocampal microglia and neuronal damage; the tumor suppression rates of positive drug and XKJR were 40.32% and 48.83%, respectively, suggesting a lower tumor growth rate than that of the model group. In summary, XKJR may improve hippocampal microglia activation and neuronal damage in mice with breast cancer related depression through activating COX signaling pathway.

Modulation of the prostaglandin-endoperoxide synthase 2 gene expression by variant haplotypes: influence of the 3'-untranslated region

The inducible inflammatory enzyme cycloxigenase-2 is up-regulated in cancer, and favors tumor progression. Cycloxigenase-2 is encoded by the prostaglandin-endoperoxide synthase 2 (PTGS2) gene, which presents sequence variations in the promoter region (PR) and in the 3′-untranslated region (3′-UTR). Different PR (rs689465, rs689466, rs20417) and 3′-UTR (rs5275) variants were generated by site-directed mutagenesis, and combined in haplotypes to access expression levels using a reporter system (luciferase) in human cells (MCF-7 and HEK293FT). Luciferase activity did not differ significantly among PTGS2 PR constructs, except for pAAC (containing variant allele rs20417 C), with 40% less activity than pAAG (wild-type sequence) in MCF-7 cells (P<0.01). Despite the lack of individual significant differences, PTGS2 PR constructs enclosing rs689466 G (pAGG and pAGC) showed an approximate two-fold increase in luciferase activity when compared to those containing rs689466 A (pAAG, pGAC, pAAC and pGAG) in both cell lines (P<0.001 for MCF-7 and P=0.03 for HEK293FT). The effect of PTGS2 3′-UTR sequences varied between MCF-7 and HEK293FT: MCF-7 cells showed significant reduction (40-60%) in luciferase activity (at least P<0.01), whereas HEK293FT cells showed more diverse results, with an average 2-fold increase when combined constructs (PR and 3′-UTR) were compared to respective parental PR sequences. The contribution of 3′-UTR variant (rs5275) was not consistent in either cell line. Despite the modulation of the 3′-UTR, with variable effects of rs5275, the enhancing transcriptional effect of rs689466 G was still detectable (P<0.0001 in MCF-7 or P=0.03 in HEK293FT cells).

Polymorphism of the cox-2 gene and susceptibility to colon and rectal cancer / Polimorfismo do gene cox-2 e a suscetibilidade ao câncer de cólon e reto

ABSTRACT Background: The colorectal neoplasm is the fourth most common malignancy among males and the third among females. In the Western world is estimated that 5% of the population will develop it, making this disease a major public health problem. Aim: To analyze the prevalence of the polymorphism -765G / C region of the COX-2 gene in colorectal cancer patients compared to a control group, analyzing the possible association between this polymorphism and susceptibility to colorectal cancer. Method: This is a case-control study with 85 participants. Were selected 25 with colorectal cancer (case group) and 60 participants without colorectal neoplasia (control group). The molecular genetic analysis was perform to identify the polymorphism -765G / C COX2 gene with standard literature technique. In addition, patient's clinical and pathological data were analyzed. Results: There was a light increase in prevalence between men in the case group, although this difference was not statistically significant. The results showed a high prevalence of GC and CC genotype in individuals with colorectal cancer, demonstrating an association between the presence of the polymorphism in the COX2 gene and susceptibility to colorectal cancer in this pattern (p=0.02). Similarly, there was also difference in allele frequencies in the groups. When patients with cancer were separated by tumor location, there was a higher prevalence of polymorphism in the left colon (p=0.02). Conclusion: The polymorphism in the COX2 gene is associated with increased susceptibility to colorectal cancer, specially rectosigmoid tumors.

RESUMO Racional: A neoplasia colorretal representa a quarta malignidade mais comum entre homens e a terceira entre as mulheres. No mundo ocidental estima-se que 5% da população a desenvolverá, tornando-a grave problema de saúde pública. Objetivo: Analisar a prevalência de polimorfismo na região -765G/C do gene COX-2 em pacientes com câncer colorretal em relação a um grupo controle, analisando a possível associação entre este polimorfismo e a suscetibilidade a ele. Método: Foram incluídos neste estudo caso-controle 85 participantes. Selecionou-se 25 com neoplasia colorretal (grupo caso) e 60 pacientes sem neoplasia colorretal (grupo controle). Realizou-se análise genético-molecular para identificação do polimorfismo -765G/C do gene COX2 com técnica padrão da literatura. Além disso, foram levantados dados clínicos e anatomopatológicos dos pacientes. Resultado: Constatou-se discreto aumento de prevalência entre os homens no grupo caso, embora esta diferença não fosse estatisticamente significante. Os resultados revelaram alta prevalência do genótipo GC e CC nos indivíduos com câncer colorretal, demonstrando associação entre a presença do polimorfismo no gene COX2 e a suscetibilidade ao câncer colorretal nesta amostra (p=0,02). Similarmente, também se observou diferença nas frequências alélicas em relação aos grupos. Quando os pacientes com a neoplasia foram separados por localização do tumor, verificou-se maior prevalência do polimorfismo em pacientes de cólon esquerdo (p=0,02). Conclusão: O polimorfismo no gene COX2 está associado com a maior suscetibilidade ao câncer colorretal, especialmente em tumores do retossigmoide.

Comparison of pharmacological and genetic inhibition of cyclooxygenase-2: effects on adult neurogenesis in the hippocampal dentate gyrus

Inducible cyclooxygenase-2 (COX-2) has received much attention because of its role in neuro-inflammation and synaptic plasticity. Even though COX-2 levels are high in healthy animals, the function of this factor in adult neurogenesis has not been clearly demonstrated. Therefore, we performed the present study to compare the effects of pharmacological and genetic inhibition of COX-2 on adult hippocampal neurogenesis. Physiological saline or the same volume containing celecoxib was administered perorally every day for 5 weeks using a feeding needle. Compared to the control, pharmacological and genetic inhibition of COX-2 reduced the appearance of nestin-immunoreactive neural stem cells, Ki67-positive nuclei, and doublecortin-immunoreactive neuroblasts in the dentate gyrus. In addition, a decrease in phosphorylated cAMP response element binding protein (pCREB) at Ser133 was observed. Compared to pharmacological inhibition, genetic inhibition of COX-2 resulted in significant reduction of neural stem cells, cell proliferation, and neuroblast differentiation as well as pCREB levels. These results suggest that COX-2 is part of the molecular machinery that regulates neural stem cells, cell proliferation, and neuroblast differentiation during adult hippocampal neurogenesis via pCREB. Additionally, genetic inhibition of COX-2 strongly reduced neural stem cell populations, cell proliferation, and neuroblast differentiation in the dentate gyrus compared to pharmacological inhibition.

The potential role of COX-2 in cancer stem cell-mediated canine mammary tumor initiation: an immunohistochemical study

Increasing evidence suggests that cancer stem cells (CSCs) are responsible for tumor initiation and maintenance. Additionally, it is becoming apparent that cyclooxygenase (COX) signaling is associated with canine mammary tumor development. The goals of the present study were to investigate COX-2 expression patterns and their effect on CSC-mediated tumor initiation in primary canine mammary tissues and tumorsphere models using immunohistochemistry. Patterns of COX-2, CD44, octamer-binding transcription factor (Oct)-3/4, and epidermal growth factor receptor (EGFR) expression were examined in malignant mammary tumor (MMT) samples and analyzed in terms of clinicopathological characteristics. COX-2 and Oct-3/4 expression was higher in MMTs compared to other histological samples with heterogeneous patterns. In MMTs, COX-2 expression correlated with tumor malignancy features. Significant associations between COX-2, CD44, and EGFR were observed in low-differentiated MMTs. Comparative analysis showed that the levels of COX-2, CD44, and Oct-3/4 expression varied significantly among TSs of three histological grades. Enhanced COX-2 staining was consistently observed in TSs. Similar levels of staining intensity were found for CD44 and Oct-3/4, but EGFR expression was weak. Our findings indicate the potential role of COX-2 in CSC-mediated tumor initiation, and suggest that COX-2 inhibition may help treat canine mammary tumors by targeting CSCs.

beta-irradiation (166Ho patch)-induced skin injury in mini-pigs: effects on NF-kappaB and COX-2 expression in the skin

In the present study, the detrimental effect of beta-emission on pig skin was evaluated. Skin injury was modeled in mini-pigs by exposing the animals to 50 and 100 Gy of beta-emission delivered by 166Ho patches. Clinicopathological and immunohistochemical changes in exposed skin were monitored for 18 weeks after beta-irradiation. Radiation induced desquamation at 2~4 weeks and gradual repair of this damage was evident 6 weeks after irradiation. Changes in basal cell density and skin depth corresponded to clinically relevant changes. Skin thickness began to decrease 1 week after irradiation, and the skin was thinnest 4 weeks after irradiation. Skin thickness increased transiently during recovery from irradiation-induced skin injury, which was evident 6~8 weeks after irradiation. Epidermal expression of nuclear factor-kappa B (NF-kappaB) differed significantly between the untreated and irradiated areas. One week after irradiation, cyclooxygenase-2 (COX-2) expression was mostly limited to the basal cell layer and scattered among these cells. High levels of COX-2 expression were detected throughout the full depth of the skin 4 weeks after irradiation. These findings suggest that NF-kappaB and COX-2 play roles in epidermal cell regeneration following beta-irradiation of mini-pig skin.

Cyclooxygenase 2 in Gastric Carcinoma Is Expressed in Doublecortin- and CaM Kinase-Like-1-Positive Tuft Cells

BACKGROUND/AIMS: Doublecortin and CaM kinase-like-1 (DCAMKL1) is a marker of stem cells expressed predominantly in the crypt base in the intestine. However, DCAMKL1-positive cells have been shown to be differentiated tuft cells rather than quiescent progenitors. Tuft cells are the only epithelial cells that express cyclooxygenase 2 (COX-2) in the normal intestinal epithelium. We previously generated Cdx2-transgenic mice as model mice for intestinal metaplasia and gastric carcinoma. In the current study, we investigated the association between COX-2 and DCAMKL1 in gastric carcinoma. METHODS: We examined the association between COX-2 and DCAMKL1 expression in gastric carcinomas in clinical samples (early gastric well-differentiated adenocarcinoma) and Cdx2-transgenic mice; and the DCAMKL1-transgenic mouse stomach using immunohistochemistry and quantitative real-time polymerase chain reaction. RESULTS: The COX-2-expressing cells were scattered, not diffusely expressed, in gastric carcinomas from humans and Cdx2-transgenic mice. DCAMKL1-positive cells were also scattered in the gastric carcinomas, indicating that tuft cells could still be present in gastric carcinoma. COX-2 was expressed in DCAMKL1-positive tuft cells in Cdx2- and DCAMKL1-transgenic mouse stomachs, whereas the Sox9 transcription factor was ubiquitously expressed in gastric carcinomas, including COX-2-positive cells. CONCLUSIONS: COX-2 is expressed in DCAMKL1-expressing quiescent tuft cells in gastric carcinoma.

Investigation of cytocrom c oxidase gene subunits expression on the Multiple sclerosis.

INTRODUCTION: Multiple sclerosis (MS) is an autoimmune inflamatory disease, which affects the (Central Nervous System) and leads to the destruction of myelin and atrophy of the axons. Genetic factors, in addition to environmental ones, seem to play a role in MS. Numerous studies have reported mitochondrial defects including a reduction in cytochrome c oxidase (COX) complex function related to the reduction of mitochondrial genes expression in the cortex tissue of patients with MS have been reported. MATERIALS AND METHODS: This study aimed to assess COX5B and COX2 genes expression in MS patients and compare it with normal subjects. We determine expression levels of genes COX5B and COX2, and also gene reference ß-actine using real–time polymerase chain reaction (RT-PCR) method. Data were obtained and obtained and standardized with the gene reference and were analyzed using independent sample t-test with SPSS and Excel programs. RESULT AND DISCUSSION: The resultshowed COX5B gene expression reduced significant in MS patients compared to normal subjects (P < −0.05) whereas, there was no significant difference in the COX2 gene expression between normal subjects and patients. Thus, it can be claimed that down-regulation of mitochondrial electron transport chain genes supported the hypothesis that hypoxia-like tissue injury in MS may be due to mitochondrial genes, different expression impairment.

Cyclooxygenase-2 Polymorphisms and Susceptibility to Colorectal Cancer: A Meta-Analysis

PURPOSE: Four polymorphisms, -765G>C, -1195G>A, 8473T>C, and Val511Ala, in the cyclooxygenase-2 (COX-2) gene were identified to be associated with colorectal cancer (CRC) risk. However, the results are inconsistent. The objective of this meta-analysis was to evaluate the association between these four polymorphisms and the risk of CRC. MATERIALS AND METHODS: All eligible case-control studies published up to December 2012 on the association between the four polymorphisms of COX-2 and CRC risk were identified by searching PubMed and Web of Science. The CRC risk associated with the four polymorphisms of the COX-2 gene was estimated for each study by odds ratio (OR) together with its 95 % confidence interval (CI), respectively. RESULTS: A total of 15 case-control studies were included. Overall, no evidence has indicated that the -1195A allele, -765C allele, 8473C allele, and 511Ala allele are associated with susceptibility to CRC (-1195G>A: OR=1.11, 95 % CI: 0.82-1.51, p=0.78; -765G>C: OR=1.08, 95 % CI: 0.96-1.21, p=0.07; 8473T>C: OR=1.03, 95 % CI: 0.89-1.18, p=0.91; Val511Ala: OR=0.71, 95 % CI: 0.46-1.09, p=0.94). However, stratified analysis with ethnicity indicated that individuals with -765GC or GC/CC genotypes had an increased risk of CRC among Asian populations (GC vs. GG: OR=1.05, 95 % CI: 0.87-1.28, p=0.03; GC+CC vs. GG: OR=1.08, 95 % CI: 0.96-1.21, p=0.07). CONCLUSION: This meta-analysis indicated that -765G>C polymorphism was significantly associated with susceptibility to CRC in Asian populations.

Chemopreventive and metabolic effects of inulin on colon cancer development

Prebiotics modulate microbial composition and ensure a healthy gastrointestinal tract environment that can prevent colon cancer development. These natural dietary compounds are therefore potential chemopreventive agents. Thirty Sprague-Dawley rats (4 months old) were experimentally treated with procarcinogen dimethylhydrazine to induce colon cancer development. The rats were randomly assigned to three groups: a control group (CG), a group treated with dimethylhydrazine (DMH), and a group given DMH and inulin, a prebiotic (DMH+PRE). The effects of inulin on the activities of bacterial glycolytic enzymes, short-chain fatty acids, coliform and lactobacilli counts, cytokine levels, and cyclooxygenase-2 (COX-2) and transcription nuclear factor kappa beta (NFkappaB) immunoreactivity were measured. Inulin significantly decreased coliform counts (p < 0.01), increased lactobacilli counts (p < 0.001), and decreased the activity of beta-glucuronidase (p < 0.01). Butyric and propionic concentrations were decreased in the DMH group. Inulin increased its concentration that had been reduced by DMH. Inulin decreased the numbers of COX-2- and NFkappaB-positive cells in the tunica mucosae and tela submucosae of the colon. The expression of IL-2, TNFalpha, and IL-10 was also diminished. This 28-week study showed that dietary intake of inulin prevents preneoplastic changes and inflammation that promote colon cancer development.

A study on expression pattern of cyclooxygenase-2 in carcinoma of cervix.

Objective: The purpose of the present study was to determine the differential expression pattern of cyclooxygenase-2 (COX-2) in patients of carcinoma of uterine cervix and its correlation with tumor differentiation and lymphovascular invasion. Materials and Methods: Seventy (70) cases of cervical carcinoma were included (20 in-situ, 42 invasive squamous cell, and 8 cases of adenocarcinoma). Formalin-fixed paraffin-embedded tissue sections were stained by Hematoxylin and Eosin. Immunohistochemistry for COX-2 were performed on these blocks. Results: A higher expression of COX-2 was seen in invasive squamous cell carcinoma than in in-situ carcinoma (P = 0.002). Five out of eight cases of adenocarcinoma showed strong positivity for COX-2 antibody. Among the histopathological correlates, tumor differentiation did not show a positive correlation (P = 0.717), while lymphovascular invasion was associated with positive staining in majority of the cases (P = 0.001). Conclusion: Expression of COX-2 is more in cases of invasive than in in-situ carcinoma. Adenocarcinomas showed a strong expression of COX-2. A positive association of COX-2 expression and the presence of lymphovascular emboli were found in the present study. COX-2 inhibitors need to be studied as a therapeutic adjunct for the treatment of carcinoma cervix.

Expression of IL-17 and COX2 gene in peripheral blood leukocytes of vitiligo patients

Vitiligo is a pigmentation disorder in which inflammatory mediators such as cytokines have a pivotal role in disease's pathogenesis. Interleukin 17 [IL-17A] is a proinflammatory cytokine which is involved in the induction of several proinflamatory mediators such as cyclooxygenase 2 [COX2]. The aim of this study was to investigate the gene expression of IL-17 and COX2 in peripheral blood leukocytes of vitiligo's patients. Peripheral blood leukocytes from 15 patients with vitiligo and 15 healthy controls were separated using a gradient density centrifugation method. After total RNA isolation and cDNA synthesis, IL-17 and COX2 gene expression were quantified by real-time polymerase chain reaction [PCR]. There were no significant differences in IL-17 and COX2 gene expression in lymphocytes of patients with vitiligo compared with control group [p<0.05]. However there was an increased IL-17 and COX2 gene expression in neutrophils of patients compared to controls, but it did not reach statistical significance [p=0.05]. We could not find any differences in IL-17 and Cox2 gene expression between clinical diseases subtypes, sex and age. There was a significant correlation between IL-17 and COX2 genes expression in the neutrophils of patients [p=0.00, r=0.80]. Our results showed an increased expression in IL-17 and Cox-2 genes in neurophils of patients with vitiligo. This suggested that these two factors are involved in the inflammatory process. Further studies with a larger sample size might help to establish the role of these factors in the pathogenesis of diseases

Rottlerin enhances IL-1beta-induced COX-2 expression through sustained p38 MAPK activation in MDA-MB-231 human breast cancer cells

Cyclooxygenase-2 (COX-2) is an important enzyme in inflammation. In this study, we investigated the underlying molecular mechanism of the synergistic effect of rottlerin on interleukin1beta (IL-1beta)-induced COX-2 expression in MDA-MB-231 human breast cancer cell line. Treatment with rottlerin enhanced IL-1beta-induced COX-2 expression at both the protein and mRNA levels. Combined treatment with rottlerin and IL-1beta significantly induced COX-2 expression, at least in part, through the enhancement of COX-2 mRNA stability. In addition, rottlerin and IL-1beta treatment drove sustained activation of p38 Mitogen-activated protein kinase (MAPK), which is involved in induced COX-2 expression. Also, a pharmacological inhibitor of p38 MAPK (SB 203580) and transient transfection with inactive p38 MAPK inhibited rottlerin and IL-1beta-induced COX-2 upregulation. However, suppression of protein kinase C delta (PKC delta) expression by siRNA or overexpression of dominant-negative PKC delta (DN-PKC-delta) did not abrogate the rottlerin plus IL-1beta-induced COX-2 expression. Furthermore, rottlerin also enhanced tumor necrosis factor-alpha (TNF-alpha), phorbol myristate acetate (PMA), and lipopolysaccharide (LPS)-induced COX-2 expression. Taken together, our results suggest that rottlerin causes IL-1beta-induced COX-2 upregulation through sustained p38 MAPK activation in MDA-MB-231 human breast cancer cells.

Effect of Pertussis Toxin and Herbimycin A on Proteinase-Activated Receptor 2-Mediated Cyclooxygenase 2 Expression in Helicobacter pylori-Infected Gastric Epithelial AGS Cells

Helicobacter pylori (H. pylori) is an important risk factor for chronic gastritis, peptic ulcer, and gastric cancer. Proteinase-activated receptor 2 (PAR2), subgroup of G-protein coupled receptor family, is highly expressed in gastric cancer, and chronic expression of cyclooxygenase-2 (COX-2) plays an important role in H. pylori-associated gastric carcinogenesis and inflammation. We previously demonstrated that H. pylori induced the expression of PAR2 and COX-2 in gastric epithelial cells. Present study aims to investigate whether COX-2 expression induced by H. pylori in Korean isolates is mediated by PAR2 via activation of Gi protein and Src kinase in gastric epithelial AGS cells. Results showed that H. pylori-induced COX-2 expression was inhibited in the cells transfected with antisense oligonucleotide for PAR2 or treated with Gi protein blocker pertussis toxin, Src kinase inhibitor herbimycin A and soybean trypsin inbitor, indicating that COX-2 expression is mediated by PAR2 through activation of Gi protein and Src kinase in gastric epithelial cells infected with H. pylori in Korean isolates. Thus, targeting the activation of PAR2 may be beneficial for prevention or treatment of gastric inflammation and carcinogenesis associated with H. pylori infection.

Endoplasmic reticulum stress (ER-stress) by 2-deoxy-D-glucose (2DG) reduces cyclooxygenase-2 (COX-2) expression and N-glycosylation and induces a loss of COX-2 activity via a Src kinase-dependent pathway in rabbit articular chondrocytes

Endoplasmic reticulum (ER) stress regulates a wide range of cellular responses including apoptosis, proliferation, inflammation, and differentiation in mammalian cells. In this study, we observed the role of 2-deoxy-D-glucose (2DG) on inflammation of chondrocytes. 2DG is well known as an inducer of ER stress, via inhibition of glycolysis and glycosylation. Treatment of 2DG in chondrocytes considerably induced ER stress in a dose- and time-dependent manner, which was demonstrated by a reduction of glucose regulated protein of 94 kDa (grp94), an ER stress-inducible protein, as determined by a Western blot analysis. In addition, induction of ER stress by 2DG led to the expression of COX-2 protein with an apparent molecular mass of 66-70kDa as compared with the normally expressed 72-74 kDa protein. The suppression of ER stress with salubrinal (Salub), a selective inhibitor of eif2-alpha dephosphorylation, successfully prevented grp94 induction and efficiently recovered 2DG-modified COX-2 molecular mass and COX-2 activity might be associated with COX-2 N-glycosylation. Also, treatment of 2DG increased phosphorylation of Src in chondrocytes. The inhibition of the Src signaling pathway with PP2 (Src tyrosine kinase inhibitor) suppressed grp94 expression and restored COX-2 expression, N-glycosylation, and PGE2 production, as determined by a Western blot analysis and PGE2 assay. Taken together, our results indicate that the ER stress induced by 2DG results in a decrease of the transcription level, the molecular mass, and the activity of COX-2 in rabbit articular chondrocytes via a Src kinase-dependent pathway.

Cox-2 and IL-10 Polymorphisms and Association with Squamous Cell Carcinoma of The Head and Neck in a Korean Sample

Cyclooxygenase-2 (COX-2) is involved in inflammation and carcinogenesis. Interleukin-10 (IL-10) is also regarded as anti-inflammatory factors with the multi-functional ability to positively and negatively influence functional immunity and tumor development. Genetic polymorphisms of COX-2 and IL-10 might contribute to the development of squamous cell carcinoma of the head and neck (SCCHN). The purpose of this study was to evaluate the association of COX-2 and IL-10 single nucleotide polymorphisms (SNPs) with the risk of SCCHN in a Korean sample. We analyzed the COX-2 SNPs, -1329A>G, +1266C>T, and +6365T>C, and the IL-10 SNPs, -1082A>G, +920T>G, and +3917T>C, in 290 Korean SCCHN patients and 358 healthy controls. There was no significant association between the risk of SCCHN and the three COX-2 or three IL-10 SNPs. We analyzed three haplotypes (ht1, ht2, ht3) for COX-2 and found that COX-2 ht3+/+ was associated with a decreased risk of SCCHN in a Korean sample, compared with the COX-2 ht3 -/- genotype (P=0.03). Two haplotypes (ht1, ht2) of IL-10 were analyzed and there was no statistical significance in the distribution of haplotypes. Based on these results, the COX-2 haplotype ht3 can be used as a molecular biomarker to predict low risk groups of SCCHN in a Korean sample.

Ethanol extract of Angelica gigas inhibits croton oil-induced inflammation by suppressing the cyclooxygenase - prostaglandin pathway

The anti-inflammatory effects of an ethanol extract of Angelica gigas (EAG) were investigated in vitro and in vivo using croton oil-induced inflammation models. Croton oil (20 microgram/mL) up-regulated mRNA expression of cyclooxygenase (COX)-I and COX-II in the macrophage cell line, RAW 264.7, resulting in the release of high concentrations of prostaglandin E2 (PGE2). EAG (1~10 microgram/mL) markedly suppressed croton oil-induced COX-II mRNA expression and PGE2 production. Application of croton oil (5% in acetone) to mouse ears caused severe local erythema, edema and vascular leakage, which were significantly attenuated by oral pre-treatment with EAG (50~500 mg/kg). Croton oil dramatically increased blood levels of interleukin (IL)-6 and PGE2 without affecting tumor-necrosis factor (TNF)-alpha and nitric oxide (NO) levels. EAG pre-treatment remarkably lowered IL-6 and PGE2, but did not alter TNF-alpha or NO concentrations. These results indicate that EAG attenuates inflammatory responses in part by blocking the COX-PGE2 pathway. Therefore, EAG could be a promising candidate for the treatment of inflammatory diseases.

Cyclooxygenase-2 Expression Is Related to the Epithelial-to-Mesenchymal Transition in Human Colon Cancers

PURPOSE: Down-regulation of E-cadherin is a hallmark of the epithelial-to-mesenchymal transition (EMT). EMT progression in cancer cells is associated with the loss of certain epithelial markers and the acquisition of a mesenchymal phenotype, as well as migratory activities. Cyclooxygenase-2 (COX-2) expression is associated with tumor invasion and metastasis in colon cancer. This study investigated the relationship between E-cadherin and COX-2 in colon cancer cells and human colon tumors. MATERIALS AND METHODS: Colon cancer cell lines and immunohistochemistry were used. RESULTS: E-cadherin expression was inversely related to the expressions of COX-2 and Snail in colon cancer cells. Ectopic expression of COX-2 or Snail reduced E-cadherin and induced a scattered, flattened phenotype with few intercellular contacts in colon cancer cells. Treatment of cancer cells with phorbol 12-myristate 13-acetate increased the expressions of COX-2 and Snail, decreased 15-hydroxyprostaglandin dehydrogenase expression, and increased the cells' motility. In addition, exposure to prostaglandin E2 increased Snail expression and cell motility, and decreased E-cadherin expression. Membranous E-cadherin expression was lower in adenomas and cancers than in the adjacent, non-neoplastic epithelium. In contrast, the expressions of Snail and COX-2 were higher in cancers than in normal tissues and adenomas. The expressions of COX-2 and Snail increased in areas with abnormal E-cadherin expression. Moreover, COX-2 expression was related to higher tumor stages and was significantly higher in nodal metastatic lesions than primary cancers. CONCLUSION: This study suggests that COX-2 may have a role in tumor metastasis via EMT.

AMP kinase/cyclooxygenase-2 pathway regulates proliferation and apoptosis of cancer cells treated with quercetin

AMPK (AMP-activated protein kinase) is highly conserved in eukaryotes, where it functions primarily as a sensor of cellular energy status. Recent studies indicate that AMPK activation strongly suppresses cell proliferation in non-malignant cells as well as in tumor cells. In this study, quercetin activated AMPK in MCF breast cancer cell lines and HT-29 colon cancer cells, and this activation of AMPK seemed to be closely related to a decrease in COX-2 expression. The application of a COX-2 inhibitor or cox-2(-/-) cells supported the idea that AMPK is an upstream signal of COX-2, and is required for the anti-proliferatory and pro-apoptotic effects of quercetin. The suppressive or growth inhibitory effects of quercetin on COX-2 were abolished by treating cancer cells with an AMPK inhibitor Compound C. These results suggest that AMPK is crucial to the anti-cancer effect of quercetin and that the AMPK-COX-2 signaling pathway is important in quercetin-mediated cancer control.

Differential regulation of inducible nitric oxide synthase and cyclooxygenase-2 expression by superoxide dismutase in lipopolysaccharide stimulated RAW 264.7 cells

Inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) have been known to be involved in various pathophysiological processes such as inflammation. This study was performed to determine the regulatory function of superoxide dismutase (SOD) on the LPS-induced expression of iNOS, and COX-2 in RAW 264.7 cells. When a cell-permeable SOD, Tat-SOD, was added to the culture medium of RAW 264.7 cells, it rapidly entered the cells in a dose-dependent manner. Treatment of RAW 264.7 cells with Tat-SOD led to decrease in LPS-induced ROS generation. Pretreatment with Tat-SOD significantly inhibited LPS-induced expression of iNOS and NO production but had no effect on the expression of COX-2 and PGE2 production in RAW 264.7 cells. Tat-SOD inhibited LPS-induced NF-kappaB DNA binding activity, IkappaBalpha degradation and activation of MAP kinases. These data suggest that SOD differentially regulate expression of iNOS and COX-2 in LPS-stimulated RAW 264.7 cells.