Cyclooxygenase (COX) is the obligate, rate-limiting enzyme for the conversion of arachidonic acid into prostaglandins, which mediate mitogenesis, apoptosis, angiogenesis, blood flow, secondary injury, and inflammation. COX is consist of 2 subtypes: COX-1 and COX-2. In recent years, there are a number of lines of evidence that COX-1 and COX-2 play a important in role brain injuries.
Animals ; Apoptosis/drug effects* ; Brain Injuries/pathology* ; Cyclooxygenase 1/metabolism* ; Cyclooxygenase 2/metabolism* ; Cyclooxygenase Inhibitors/therapeutic use* ; Humans ; Immunohistochemistry ; Neurons/drug effects* ; Rats ; Time Factors

Cyclooxygenase 2 ; metabolism ; Cyclooxygenase Inhibitors ; pharmacology ; Hep G2 Cells ; Humans ; Nitrobenzenes ; pharmacology ; Radiation Tolerance ; drug effects ; Sulfonamides ; pharmacology

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.
Animals ; Celecoxib/*pharmacology ; Cell Differentiation/drug effects/physiology ; Cell Proliferation/drug effects/physiology ; Cyclooxygenase 2/*genetics/metabolism ; Cyclooxygenase 2 Inhibitors/*pharmacology ; Dentate Gyrus/drug effects/*physiology ; Male ; Mice ; Mice, Knockout ; Neural Stem Cells/drug effects/physiology ; Neurogenesis/drug effects

OBJECTIVETo investigate anticancer effect and molecular mechanism of N-[(Cyclohexyloxy)-4-nitrophenyl] methanesulfonamide on HepG2 cells in vitro.

METHODSHepG2 cells were treated with various concentrations (100, 200, 300, 400 micromol/L) of NS-398 [selective for cyclooxygenase 2 (COX-2) inhibition]. Cell growth was measured by MTT method, DNA fragmentation gel analysis was used to analyze the apoptosis cells, DNA ploidy and apoptotic cell percentage were examined by flow cytometry (FCM). PGE2 concentration was measured by radioimmunoassay method. The expressions of COX-2 were also examined by Western blot analysis.

RESULTSNS-398 inhibited HepG2 cell proliferation and induced apoptosis in a concentration-dependent manner. DNA ploidy analysis showed that S phase cells were significantly decreased and quiescent G1 phase was accumulated with NS-398 concentration increasing. The IC50 of 24 hours was 300 micromol/L. The release of PGE2 was significantly reduced in HepG2 cells with the values of NS-398 being (0.70 +/- 0.02), (0.48 +/- 0.02), (0.29 +/- 0.01) and (0.18 +/- 0.01) respectively, as compared with control group (0.03 +/- 0.01). NS-398 could inhibit the activity and expression of COX-2, with higher concentration, it can significantly down-regulate the expression of COX-2 (t = 3.736, 1.623, 1.810, 2.587, P < 0.01).

CONCLUSIONNS-398 might significantly inhibit the proliferation of HepG2 cells and induce apoptosis. The mechanisms were related with the accumulation of quiescent G1 phase and the inhibition of COX-2 activity.

Apoptosis ; drug effects ; Cell Line, Tumor ; metabolism ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; biosynthesis ; Humans ; Nitrobenzenes ; pharmacology ; Sulfonamides ; pharmacology

OBJECTIVETo study the inhibitory effects of c9, t11-conjugated linoleic acid (c9, t11-CLA) on migration of human gastric carcinoma cell line (SGC-7901) via cyclooxygenase-2 (COX-2) pathway.

METHODSAfter inhibiting COX-2 activity by 100 micromol/L COX-2 inhibitor NS-398 in SGC-7901 cell, we treated SGC-7901 cells with c9, t11-CLA at a concentration of 200,100, 50, 25 micromol/L for 24 h, respectively. Using reconstituted basement membrane invasion, adhesion, chemotaxis assays, we detected the effect of c9, t11-CLA and COX-2 on the cell migration.

RESULTSCompared to NS-398 group, 200, 100 micromol/L c9, t11-CLA significantly suppressed SGC-7901 cells invading into the reconstituted basement membrane (F = 14.309, P = 0.000; F = 19.005, P = 0.000). 200 micromol/L c9, t11-CLA significantly inhibited SGC-7901 cells adhering to laminin, fibronectin and Matrigel (F = 3.063, P = 0.021; F = 6.692, P = 0.001; F = 11.999, P = 0.000). The chemotaxis of SGC-7901 cells and inhibitory frequency were significantly decreased in the 200 micromol/L c9, t11-CLA group (F = 1.380, P = 0.276).

CONCLUSIONc9, t11-CLA inhibits invasion, adhesion and chemotaxis of SGC-7901 cells, and the COX-2 plays an important role in the process. [ Key words]

Cell Movement ; drug effects ; physiology ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase 2 Inhibitors ; pharmacology ; Humans ; Linoleic Acid ; metabolism ; pharmacology ; Neoplasm Invasiveness ; Stomach Neoplasms ; metabolism ; pathology ; Tumor Cells, Cultured

OBJECTIVETo investigate the effects of the selective cyclooxygenase-2 (COX-2) inhibitor NS398 on the growth of human pancreatic tumor BxPC-3 cell strain and its possible mechanisms.

METHODSThe effect of NS398 on cell growth was assessed by 3- (4,5-dimethylthiazol-2-yl) -2, 5-diphenyl thiazolyl blue (MTT) assay. Apoptosis was determined by fluorescence-activated cell scanning (FACS) analysis and assessment of the floating cell/attached cell ratio. Caspase-3 activation was evaluated by Active Caspase-3 Apoptosis Kit with flow cytometry. Reverse transcriptase-polymerase chain reaction analysis (RT-PCR) and Western blot were used to demonstrate expression levels of COX-1, COX-2 mRNA, and protein, as well as Caspase-3 protein in pancreatic tumor BxPC-3 cell strain.

RESULTSSelective COX-2 inhibitor NS398 significantly decreased cell viability and induced apoptosis in pancreatic tumor BxPC-3 cell strain. The protein expression of Caspase-3 was induced by high-concentration NS398. Caspase-3 activity was strongly activated by NS398.

CONCLUSIONSSelective COX-2 inhibitor NS398 has antiproliferative and proapoptotic potential in pancreatic tumor BxPC-3 cells. Such effect is independent of COX-2, but correlates with Caspase-3 activation.

Apoptosis ; drug effects ; Caspase 3 ; drug effects ; metabolism ; Cyclooxygenase 1 ; metabolism ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase Inhibitors ; pharmacology ; Humans ; Nitrobenzenes ; pharmacology ; Pancreatic Neoplasms ; enzymology ; pathology ; Sulfonamides ; pharmacology ; Tumor Cells, Cultured

BACKGROUNDCigarette smoking has been verified as the risk factor of esophageal squamous cell carcinoma (ESCC). Overexpression of cyclooxygenase 2 (COX-2) is shown in ESCC. The objective of this study was to investigate the effects of cigarette smoking ethanol extract (EE) on the proliferation of the human ESCC cell lines, and to explore the correlation between the proliferation rate of human ESCC cell lines and the expression pattern of COX-2. Whether aspirin can inhibit the proliferation of the ESCC cell lines pretreated with EE, and regulate the mRNA expression levels of COX-2 are also examined.

METHODSTwo human ESCC cell lines were selected. EC109 was poorly differentiated and EC9706 was highly differentiated. EC109 and EC9706 were treated with EE and aspirin for different time course. The cell growth of ESCC was measured by MTT reduction assay and the expression of COX-2 was measured by RT-PCR and Western blot analysis.

RESULTSEE promoted the proliferation of EC109 and EC9706 in dose- and time-dependent manners. In the concentration range (10 - 100 microg/ml for EE) and in the time range (24 - 72 hours) after addition of EE, the cell proliferation was prominent in an up-scaled manner respectively. Aspirin could inhibit the proliferation of cell lines EC109 and EC9706, pretreated with EE for 5 hours, in a dose-dependent manner. In the concentration range (0.5 - 8.0 mmol/L for aspirin), the cell growth inhibition was prominent in an up-scaled manner accordingly (P < 0.05). The effect of EE on cell proliferation was correlated with the up-regulation of COX-2 gene. However, the cell growth inhibition of aspirin was correlated with the down-regulation of COX-2 gene.

CONCLUSIONSEE can stimulate the proliferation of human ESCC cell lines EC109 and EC9706, most likely through up-regulating the expression of COX-2. Aspirin can inhibit the proliferation of ESCC cell lines induced by EE, which suggests it may be advantageous in the chemoprevention and therapy of human tobacco-related ESCC. And its effect is likely to be related with modulating COX-2 activity.

Aspirin ; pharmacology ; Carcinoma, Squamous Cell ; drug therapy ; etiology ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; physiology ; Cyclooxygenase 2 Inhibitors ; pharmacology ; Esophageal Neoplasms ; drug therapy ; etiology ; pathology ; Humans ; Smoking ; adverse effects

This study was aimed to investigate the effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of human acute myeloid leukemia cell line HL-60 and its mechanism. HL-60 cells were cultured with different concentrations of celecoxib for 24 h. Cell proliferation was analyzed by CCK-8 assay, cell apoptosis and cell cycle distribution were detected by flow cytometry. Cyclin D1, cyclin E1 and COX-2 mRNA expressions were determined by RT-PCR. The results showed that after the HL-60 cells were treated with different concentrations of celecoxib for 24 h, the cell growth was significantly inhibited in a dose-dependent manner(r = 0.955), IC50 was 63.037 µmol/L of celecoxib. Celecoxib could effectively induce apoptosis in HL-60 cells also in dose-dependent manner(r = 0.988), blocked the HL-60 cells in the G0/G1 phase. The expression of cyclin D1, cyclin E1 and COX-2 mRNA were downregulated. It is concluded that celecoxib can inhibit the proliferation of HL-60 cells in dose-dependent manner, celecoxib causes cell G0/G1 arrest and induces cell apoptosis possibly through down-regulation of the cyclin D1 and cyclin E1 expression, and down-regulation of COX-2 expression respectively.
Apoptosis ; drug effects ; Celecoxib ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Cyclin E ; metabolism ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase 2 Inhibitors ; pharmacology ; Gene Expression Regulation, Leukemic ; HL-60 Cells ; Humans ; Oncogene Proteins ; metabolism ; Pyrazoles ; pharmacology ; Sulfonamides ; pharmacology

The inhibitory effects of two kinds of selective cyclooxygenase-2 inhibitors on the proliferation of human carcinoma of larynx Hep-2 in vitro and their corresponding mechanisms were investigated. Hep-2 cells were cultured with two kinds of selective cyclooxygenase-2 inhibitors (Sc-58125 and Celecoxib) at various concentrations for 24 h. Morphological changes were observed under the phase microscopy and the growth suppression was detected by using MTT colorimetric assay. Apoptotic DNA fragments were observed by agarose gel electrophoresis, and the cell cycle and apoptotic rate were detected by flow cytometry (FCM) respectively. Hep-2 cells became rounded and detached from the culture dish after being treated with Celecoxib for 24 h, however, they remained morphologically unchanged with Sc-58125. Sc-58125 could increase G2 phase cells, whereas, Celecoxib rose G1 phase cells. Both of the two effects were dose-dependent. Moreover, the Hep-2 cells cultured with 50 micromol/L and 100 micromol/L Celecoxib showed obvious apoptosis, with the nuclear DNA of cells exhibiting characteristic DNA ladder. So Sc-58125 could inhibit the proliferation of Hep-2 cells by altering the G2 phase cells. However, Celecoxib had the same effect by changing the G1 phase cells and inducing apoptosis at higher concentration.
Antineoplastic Agents/pharmacology ; Apoptosis/drug effects ; Cell Proliferation/drug effects ; Cyclooxygenase 2 Inhibitors/*pharmacology ; Dose-Response Relationship, Drug ; Laryngeal Neoplasms/*pathology ; Pyrazoles/*pharmacology ; Sulfonamides/*pharmacology ; Tumor Cells, Cultured

OBJECTIVE: To investigate the effect and mechanism of the selective COX-2 inhibitor NS-398 and carboplatin on the human cervical carcinoma cell line Hela. METHODS: The effect of NS-398, carboplatin, and both on the proliferation of Hela cells was assessed by methyl-thiazolyl tetrazolium (MTT) method, and the apoptosis assay and cell cycle distribution were analyzed by flow cytometry. RESULTS: NS-398, and carboplatin inhibited the growth of Hela cells in a dose and time-dependent manner. When combining carboplatin with NS-398, the combined inhibition rate was increased, which nearly equaled the inhibition rate of the double concentrations of carboplatin. Flow cytometry demonstrated that the cell cycle was redistributed: the G(1)-phase cell fraction was increased while the S-phase cell fraction was significantly decreased after the cells were treated with NS-398 (P<0.05), However,the result was just the opposite after being treated with carboplatin. The apoptotic rate was 1.48%+/-0.03% and 3.43%+/-0.02% for pre-treatment and post-treatment with NS-398 respectively (P>0.05) while the apoptotic rate was 9.32%+/-0.02% after the treatment with carboplatin (P<0.05). CONCLUSION NS-398 can inhibit the growth of Hela cells. The effect of NS-398 on Hela cells may not be related to the apoptosis. NS-398 and carboplatin can bring about synergistic effect in chemotherapy on Hela cells.
Apoptosis ; drug effects ; Carboplatin ; pharmacology ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 Inhibitors ; pharmacology ; Drug Synergism ; HeLa Cells ; Humans ; Nitrobenzenes ; pharmacology ; Sulfonamides ; pharmacology