OBJECTIVETo observe the changes in gene expression of cyclooxygenase (COX) during spontaneous recovery from stress ulcer in rats exposed to water immersion and restraint stress (WRS).

METHODSA rat model of stress ulcer was established by means of WRS, in which the changes in COX expression were detected with immunohistochemistry and reverse transcription (RT)-PCR.

RESULTSVery low levels of COX-2 expression were detected in the gastric mucosa of the control rats, and the expression increased significantly during the healing process of the stress ulcer (P<0.05). COX-1 expression in the gastric mucosa showed no significant difference between the control group and the stress ulcer groups during healing (P>0.05).

CONCLUSIONCOX-1 and COX-2 expressions in rat gastric mucosa during the recovery from stress ulcer participate in the recovery of the damaged mucosa possibly by mediating prostaglandin secretion.

Animals ; Cyclooxygenase 1 ; biosynthesis ; genetics ; Cyclooxygenase 2 ; biosynthesis ; genetics ; Gastric Mucosa ; enzymology ; Male ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Remission, Spontaneous ; Stomach Ulcer ; enzymology ; Stress, Physiological ; complications

OBJECTIVETo study the expressions and the significance of interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2) in the remnant stomach.

METHODSFifty-eight patients with gastrectomy were examined by upper gastrointestinal endoscopy. Two biopsy specimens were obtained from the stoma and the upper corpus gastric mucosa in the remnant stomach. mRNA was extracted from biopsy specimens to measure the IL-8 and COX-2 gene mRNA levels by real-time PCR method.

RESULTSIL-8 and COX-2 levels were higher in stoma than in corpus, IL-8 levels in BI anastomosis were significantly higher in stoma than in corpus (P< 0.05). In Hp-negative patients, IL-8 and COX-2 levels in stoma were significantly higher in BII anastomosis than in BI anastomosis (P < 0.05). In Hp-positive patients, IL-8 and COX-2 levels in stoma showed no significant differences between BII anastomosis and BI anastomosis. In corpus, IL-8 and COX-2 levels in Hp-positive patients were significantly higher than those in Hp-negative patients, (P < 0.05), including in BI anastomosis and in BII anastomosis.

CONCLUSIONSThe risk of the secondary stomach carcinogenesis in stoma after distal gastrectomy is higher than that in corpus; The types of anastomosis may influence the risk for the secondary stomach carcinogenesis in the remnant stomach mucosa.

Adult ; Aged ; Aged, 80 and over ; Female ; Gastric Mucosa ; metabolism ; microbiology ; Gastric Stump ; surgery ; Gastroenterostomy ; adverse effects ; methods ; Helicobacter Infections ; Helicobacter pylori ; Humans ; Interleukin-8 ; biosynthesis ; genetics ; Male ; Middle Aged ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; Stomach Neoplasms ; etiology

OBJECTIVETo explore the effect of matrine on cyclooxygenase-2 (COX-2) expression in colon cancer HT-29 cell line at the level of gene and protein.

METHODSLevels of mRNA and protein expression of COX-2, and its synthesized product prostaglandin E2 (PGE2) of colon cancer HT-29 cell line were detected by RT-PCR, Western-blot, ELISA respectively before and after treatment of matrine in different concentrations.

RESULTSMatrine had inhibitory effect on the mRNA and protein expression of COX-2, and synthesis of PGE2 in colon cancer HT-29 cell line, but had no effect on COX-1. When HT-29 cell line was treated with 2.0 mg/ml of matrine, the inhibitory rate on COX-2 mRNA expression were 100% at 6 hrs and 9 hrs after treatment; the inhibitory rate on PGE2 synthesis was 63.8 % at 9 hrs after treatment; and that on COX-2 protein expression was 48% and 100% 12 hrs and 24 hrs after treatment, respectively.

CONCLUSIONMatrine has selective inhibitory effect on gene transcription, protein expression and functional activity of COX-2 in HT-29 cell line, which is time-dependent and concentration-dependent within certain range of concentration and acting time.

Alkaloids ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Cyclooxygenase 2 ; Dinoprostone ; biosynthesis ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Enzymologic ; HT29 Cells ; Humans ; Membrane Proteins ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; Quinolizines ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Transcription, Genetic

OBJECTIVETo transfect antisense vector of human cyclooxygenase-2 (COX-2) gene into COX-2 highly expressing cholangiocarcinoma cell line QBC939 and explore its biological activities and role in carcinogenesis.

METHODSQBC939 cells were transfected with antisense vector of human COX-2 gene using LipoVec transfecting technique. Transfected cells were selected with G418; COX-2 mRNA was examined using reverse transcription polymerase chain reaction (RT-PCR) and COX-2 protein expression was detected by immunocytochemistry using isozyme selective antibodies. The proliferative status of transfected cells was measured by using methabenzthiazuron (MTT) assay; Cell cycle and apoptosis were analyzed by using flow cytometry.

RESULTSRT-PCR showed a lower COX-2 mRNA level in antisense vector transfected cells and immunocytochemistry showed a weaker COX-2 protein expression in antisense vector transfected cells. The antisense vector transfected cells proliferative index decreased significantly (P < 0.01), the percentage of S phase decreased remarkably (P < 0.05) in antisense vector transfected cells (9.27% +/- 1.91%) compared with that in QBC939 cells without transfection(16.35% +/- 2.87%), and the percentage of G0/G1 phase increased remarkably (P < 0.05) in antisense vector transfected cells (75.16% +/- 4.13%) compared with that in QBC939 cells without transfection (57.31% +/- 10.16%). Transfection with antisense vector of human COX-2 gene had no significant influence on the apoptosis in QBC939 cells (P > 0.05).

CONCLUSIONTransfection with antisense vector of human COX-2 gene could inhibit the proliferation of human cholangiocarcinoma QBC939 cells.

Apoptosis ; Bile Duct Neoplasms ; metabolism ; pathology ; Bile Ducts, Intrahepatic ; Cell Cycle ; Cell Division ; Cell Line, Tumor ; Cholangiocarcinoma ; metabolism ; pathology ; Cyclooxygenase 2 ; DNA, Antisense ; genetics ; Humans ; Isoenzymes ; biosynthesis ; genetics ; physiology ; Membrane Proteins ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; physiology ; RNA, Messenger ; genetics ; Transfection

Antineoplastic Agents ; pharmacology ; Bile ; physiology ; Bile Duct Neoplasms ; metabolism ; pathology ; Bile Ducts, Intrahepatic ; Celecoxib ; Cell Division ; drug effects ; Cell Line, Tumor ; Cholangiocarcinoma ; metabolism ; pathology ; Cyclooxygenase 2 ; Dinoprostone ; metabolism ; Humans ; Isoenzymes ; biosynthesis ; genetics ; Membrane Proteins ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; Pyrazoles ; RNA, Messenger ; genetics ; Sphincterotomy, Transduodenal ; adverse effects ; Sulfonamides ; pharmacology ; Up-Regulation

OBJECTIVETo study the effects of sinomenine (Sin) on cell proliferation, intracellular expression of cyclooxygenase-2 (COX-2), and production of PGE2 in lipopolysaccharide-induced PC-12 cells, To explore the Sin's mechanism on nerve cell.

METHODPC-12 cells were cultured with nerve growing factors (NGF), and pretreated with Sin at various concentrations (0, 3 x 10(-6), 30 x 10(-6), 150 x 10(-6) mol x L(-1)) for 2 hours, then with or without stimulation of lipopolysaccharide (LPS). The proliferation activity of PC-12 cells was determined by 3H-TdR incorporation, and the production of PGE2 in culture supernatants of PC-12 cells was detected with competitive ELISA. Expression of COX-2 mRNA in PC-12 cells was analyzed by semi-quantitative RT-PCR, and expression of COX-2 protein was estimated by Western blot method and cellular enzyme immunoassay. Nuclear factor-kappa B (NF-kappaB) activity in whole-cell extract of PC-12 cells was also measured by an ELISA-based method.

RESULTThe data showed that Sin down-regulated the expression of COX-2 mRNA and protein, and reduced the production of PGE2 in the LPS-stimulated PC-12 cells which correlated with Sin's concentrations positively. In addition, NF-kappaB activity in LPS-stimulated cells was suppressed significantly by Sin. No inhibition of proliferation of PC-12 cells due to Sin treatment was observed.

CONCLUSIONSin mediates the down-regulation of expression of COX-2 and production of induced PGE2 in PC-12 cells by suppressing the activity of NF-kappaB.

Animals ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; Dinoprostone ; biosynthesis ; Down-Regulation ; Lipopolysaccharides ; Morphinans ; isolation & purification ; pharmacology ; NF-kappa B ; metabolism ; PC12 Cells ; Plants, Medicinal ; chemistry ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Sinomenium ; chemistry

To study the expression of cyclooxygenase 2 (COX-2) gene and its relationship with clinicopathological characteristics of lung cancer, expression of the COX-2 mRNA was evaluated by reverse transcription polymerase chain reaction (RT-PCR) in cancerous tissues and paired adjacent non-cancerous tissues from 56 patients and benign lesions from 12 patients. Our results showed that expression of COX-2 gene was detected in a significantly greater proportion of cancerous tissues (60.7%) than adjacent noncancerous tissues (10.7%, P<0.01) and benign lesions (3/12, P<0.05). Expression of COX-2 gene was higher in adenocarcinoma than in squamous carcinoma (P<0.01). There was no significant relationship between COX-2 gene expression and patients' age, sex, histological type of tumors, differentiation degree and TNM stages (P>0.05). The up-regulation of COX-2 gene in lung cancer tissues especially in adenocarcinoma suggested that COX-2 may play a role in the lung carcinogenesis and COX-2 gene may serve as a potential therapeutic target in lung cancer.
Adenocarcinoma ; enzymology ; Adult ; Aged ; Cyclooxygenase 2 ; Female ; Humans ; Lung Neoplasms ; enzymology ; Male ; Membrane Proteins ; Middle Aged ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

To investigate the effect of N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 on the formalin-induced cyclooxygenase-2 (COX-2) expression in the dorsal horn of the rat spinal cord. Forty-eight male Sprague-Dawley rats were divided into 4 groups: control, formalin, formalin+normal saline (NS) and formalin+MK-801 groups. Rats in formalin, formalin+NS and formalin+MK-801 groups were subcutaneously injected with 0.2 ml 5% formalin into the plantar surface of the right hind paw. NS or MK-801 solution (10 microl) was intrathecally injected under transient ether anesthesia 15 min prior to the formalin injection in the formalin+NS and formalin+MK-801 groups, respectively. Flinch reflex was measured within 1 h after the formalin injection and expression of COX-2 in the dorsal horn of the L(5) segment of the spinal cord was assayed 24 h after the formalin injection using immunohistochemistry. Formalin evoked a biphasic flinch reflex. MK-801 produced a limited effect on the flinch reflex of phase 1, but produced significant and dose-dependent suppression on the flinch reflex of phase 2. The number and immunostaining density, shown by grey degree which was inversely proportional to the immunostaining density, of immunoreactive soma in the superficial (mainly I-II) and deep (IV-VI) laminae of the L(5) spinal cord in formalin and formalin+NS groups increased significantly, in contrast to those in the control group (p<0.01). The number and immunostaining density of immunoreactive soma decreased significantly in formalin+MK-801 group, in comparison with the formalin+NS group (p<0.05). The degree of the decrease was proportional to the dosage of MK-801 used. In addition, there were some immunoreactive processes especially in the superficial laminae, which extended as a continuous band across the dorsal horn after the formalin injection. Change in immunostaining density of the processes after administration of MK-801 was similar to that in the immunoreactive soma. The results showed that intrathecal injection of MK-801 significantly inhibited the increase of COX-2 expression in the spinal dorsal horn induced by the formalin injection in a dose-dependent manner, suggesting that the activation of NMDA receptor is one of the mechanisms for the formalin-induced increase of COX-2 expression in the spinal dorsal horn.
Animals ; Cyclooxygenase 2 ; Dizocilpine Maleate ; pharmacology ; Formaldehyde ; Isoenzymes ; biosynthesis ; genetics ; Posterior Horn Cells ; enzymology ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, N-Methyl-D-Aspartate ; antagonists & inhibitors ; Spinal Cord ; enzymology

OBJECTIVETo observe the effect of tetramethylpyrazine (TMP) on lipopolysaccharides (LPS) induced macrophage cyclo-oxidase-2 (COX-2) gene expression and activity in RAW264.7 mice, and to further investigate the effect and mechanism of TMP on LPS induced apoptosis of cardiac myocytes in suckling mice.

METHODSRT-PCR and Western Blot (WB) were used to investigate the macrophage COX-2 gene expression, ELISA was used to measure its activity, fluorescence microscopy was used to determine the apoptosis of murine neonatal cardiac myocyte, and fluorescence spectrophotometry was used to detect the concentration of intracellular calcium ion (Ca2+).

RESULTSTMP of 10(-6) mol/L could significantly reduce the COX-2 mRNA and protein expression (P < 0.05), in 10(-5) mol/L and 10(-4) mol/L could significantly decrease the COX-2 expression (P < 0.01) stimulated by LPS, but couldn't influence the activity of COX-2 by different TMP concentration. TMP in 10(-5) mol/L could significantly lower the concentration of intracellular Ca2+ in cardiac myocyte, and antagonize the LPS induced apoptosis of cardiac myocyte in suckling mice (P < 0.05).

CONCLUSIONTMP has the pharmacological effect in inhibiting LPS induced macrophage COX-2 expression and apoptosis of cardiac myocyte in suckling mice.

Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Cells, Cultured ; Cyclooxygenase 2 ; Isoenzymes ; biosynthesis ; genetics ; Lipopolysaccharides ; Macrophages ; enzymology ; Mice ; Myocytes, Cardiac ; cytology ; Prostaglandin-Endoperoxide Synthases ; biosynthesis ; genetics ; Pyrazines ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVESTo investigate the expression of cyclooxygenase-2 (cox-2) protein in normal squamous epithelium, squamous dysplasia and squamous cell carcinoma of the esophagus, and to elucidate the role of cox-2 in esophageal carcinogenesis.

METHODSBiopsy specimens of atypical esophageal dysplasia (n = 47) and surgical resection of squamous cell carcinoma (n = 86) were compared with normal esophageal specimens (n = 42) and the expression of cox-2 in those specimens was analyzed by immunohistochemistry and western blotting.

RESULTSA significant elevated cox-2 expression was shown in atypical esophageal squamous dysplasia and squamous cell carcinoma, as compared to that in normal esophageal squamous epithelium, with immunohistochemical stain scores of 2.67 +/- 1.77, 2.19 +/- 1.79 and 0.71 +/- 0.46, respectively. Results of western blotting analysis confirmed those obtained by immunohistochemistry. Cox-2 expression significantly correlated with proliferation activity assessed by proliferating cell nuclear antigen index in dysplastic and carcinomous lesions, respectively, and no such correlation could be found in normal esophageal mucosa. Elevated cox-2 expression was not associated with clinical-pathological features of esophageal squamous carcinoma, including age, gender, tumor size, histological grade, lymph node metastasis and clinical stage.

CONCLUSIONElevated expression of cox-2 in atypical squamous dysplasia and squamous cell carcinoma of the esophagus, which correlated with cell proliferation activity, indicated that cox-2 may be involved in the early stage of squamous carcinogenesis of the esophagus, and may be a target of prevention and treatment for esophageal squamous cell carcinoma.

Adult ; Aged ; Blotting, Western ; Cyclooxygenase 2 ; Esophageal Neoplasms ; enzymology ; pathology ; Female ; Humans ; Immunohistochemistry ; Isoenzymes ; biosynthesis ; Male ; Membrane Proteins ; Middle Aged ; Neoplasms, Squamous Cell ; enzymology ; pathology ; Prostaglandin-Endoperoxide Synthases ; biosynthesis