Atherosclerosis ; metabolism ; Cyclooxygenase 2 ; metabolism ; Humans

Cyclooxygenase-2 (Cox-2) is over-expressed in prostate cancer (PCa) and involved in its development and progression by facilitating inflammatory response, reducing cell apoptosis, increasing angiogenesis and damaging DNA oxidation. Selective Cox-2 inhibitors suppress PCa growth through various channels and therefore have a promising application value in the management of prostate cancer.
Apoptosis ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase 2 Inhibitors ; therapeutic use ; Humans ; Male ; Prostatic Neoplasms ; drug therapy ; metabolism

The cyclooxygenase (COX) is a key enzyme in the coversion of arachidonic acid to prostaglandins. COX-1 is constitutively expressed and is a critical housekeeping gene, whereas COX-2 is rapidly upregulated by growth factors and cytokines and thus responsible for inflammation. COX-2 is frequently overexpressed in colonic adenoma and carcinoma. Specific inhibitors of COX-2 have been shown to induce apoptosis in tumor cells and to inhibit tumor growth in animal models and in humans. Long-standing IBD patients have increased risk of developing colorectal cancer compared to general population. IBD-associated colorectal carcinogenesis is probably promoted by chronic inflammation and closely related to COX-2. In a recent study, powerful chemopreventive ability of selective COX-2 inhibitor was observed in colitis-related colon carcinogenesis in mouse model. But it was reported that even selective COX inhibitors aggravated the DSS-induced colonic inflammation. It is assumed that endogenous PGs are involved in the mucosal defense against DSS-induced colonic ulcerations which are produced by COX-1 at early phase and by COX-2 at late phase. Long-term use of COX-2 inhibitors for the chemoprevention of colitic cancer is needed to define their mechanism of action, that reduce side effects and have specific tumor target.
Animals ; Colitis, Ulcerative/*drug therapy ; Colonic Neoplasms/diagnosis ; Cyclooxygenase 1/metabolism ; Cyclooxygenase 2/metabolism ; Cyclooxygenase 2 Inhibitors/pharmacology/*therapeutic use ; Humans ; Mice ; Models, Animal

To investigate the relationship between the expression of cyclooxygenase-2 (COX-2) and menstrual cycle, the regulatory effects of 17-beta-estradiol (E(2)) and medroxyprogesterone acetate (MPA) on the expression of COX-2 in cervical cancer Hela cells were examined. Cervical cancer specimens were obtained from 47 pre-menopausal patients. The phase of menstrual cycle was determined by case history and HE staining of uterine endometrium. COX-2 was immunohistochemically stained by SABC staining and the staining intensity was determined with computerized image analysis system. Hela cells were incubated with alcohol, E(2), E(2)+MPA, MPA for 12, 24 and 48 h respectively. The expression of COX-2 in Hela cells was detected by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Our results showed that the expression of COX-2 was significantly higher during proliferative phase than secretory phase (P<0.05), but there was no difference in the positive rate between proliferative phase and secretory phase (P>0.05). Incubation with E(2) could significantly enhance the expression of COX-2 continually. On the contrary, E(2)+MPA and MPA alone could decrease the expression of COX-2 as compared with the control and E(2) group (P<0.05 and P<0.01 respectively). It is concluded that the expression of COX-2 in cervical cancer of pre-menopausal patients and Hela cells was regulated by estrogen/progestogen.
Cyclooxygenase 2/genetics ; Cyclooxygenase 2/*metabolism ; Estradiol/*pharmacology ; Hela Cells ; Medroxyprogesterone Acetate/*pharmacology ; Uterine Cervical Neoplasms/*enzymology

The correlation between the expression of COX-2 and p53 protein in basal cell carcinoma (BCC) of eyelid and apoptosis was investigated. Specimens of BCC were collected from 40 cases (aged 28-68 y) at the Department of Pathology, Renmin Hospital of Wuhan University, and Department of Pathology, Zhongnan Hospital of Wuhan University during from 1999 to 2006. Five specimens of paracancerous tissues served as control group. Immunohistochemical staining was performed to detect the expression of COX-2 and p53 in the tissues. The average absorbance (A) and the average positive area rate of COX-2 and p53 protein were measured by image analysis. The positive area rate of COX-2 and p53 protein was analyzed by linear correlation analysis. It was found that COX-2 and p53 proteins were highly expressed in BCC of eyelid, and weakly expressed in paracancerous tissues. Image analysis revealed that the expression of COX-2 and p53 proteins in BCC of eyelid was significantly higher than that in paracancerous tissues (P<0.01). Spearman rank correlation analysis demonstrated a positive correlation between the expression of COX-2 and p53 (r=0.113, P=0.421). It was concluded that COX-2 can increase the expression of p53 protein, therefore suppressing apoptosis.
Apoptosis ; Carcinoma, Basal Cell/*metabolism ; Cyclooxygenase 2/*metabolism ; Eyelid Neoplasms/*metabolism ; Tumor Suppressor Protein p53/*metabolism

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

OBJECTIVETo examine the chemopreventive effect of selective cyclooxygenase-2 (COX-2) inhibitor celecoxib for Barrett's esophagus in rats.

METHODSFifty 8-week-old male Sprague Dawley rats underwent esophagojejunostomy to induce Barrett's esophagus model. Four weeks after operation the animals were given celecoxib 10 mg/(kg*d(-1))(celecoxib group), or saline 1 ml (control group). Another 10 rats were sham operation group. All animals were sacrificed at 20 week after surgery. The degree of inflammation, Barrett's esophagus, adenocarcinoma, COX-2 expression and PGE(2) of animals were assessed.

RESULTAmong 60 rats, 6 rats died in celecoxib group, 8 rats died in control group, 1 rat died in sham operation group, and 45 (75%) rats completed the study. The incidence of mild, moderate and severe degree esophageal inflammation in celecoxib group and control group was 14/19(73.68%), 4/19(21.05%), 1/19(5.26%); 4/17(23.53%), 5/17(29.41%), 8/17(47.06%)(P<0.05), respectively. The incidence of Barrett's esophagus was 7/19(36.84%), 13/17(76.47%) in two group respectively(P<0.05); The incidence of Barrett's esophagus with dysplasia was 2/19(10.53%), 8/17(47.06%)(P<0.05), respectively. The expression of COX-2 was 1/7(14.29%), 10/13(76.92%)(P<0.05) in two groups. PGE2 content was significantly lower in the celecoxib group than that in control group(P<0.001). No esophageal pathological changes were found in sham operation group.

CONCLUSIONSelective COX-2 inhibitors celecoxib can inhibit inflammations, development of Barrett's esophagus and esophagus adenocarcinoma.

Animals ; Barrett Esophagus ; metabolism ; prevention & control ; Celecoxib ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase 2 Inhibitors ; therapeutic use ; Dinoprostone ; metabolism ; Male ; Pyrazoles ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sulfonamides ; therapeutic use

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

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

Animals ; Cyclooxygenase 2 ; metabolism ; Lipopolysaccharides ; Liver Failure ; metabolism ; Male ; Mice ; Mice, Inbred BALB C