Objective To study the interaction and mechanism of prostaglandin I2 (PGI2) receptor/thromboxane A2 (TxA2) receptor (IP/TP) and cyclooxygenase-2 (COX-2) in ischemia reperfusion injury after liver transplantation of rat. Methods Rats were randomly divided into three groups: control group （n=16), orthotropic liver transplantation group （n=32) and nimesulide intervention group （n=32). The samples were obtained at 3 h, 6 h, 12 h and 24 h after operation. The expressions of COX-2, IP and TP mRNA were detected by RT-PCR. Immunohistochemistry was used to detect the localization and expression of COX-2. Hematoxylin Eosin staining was used to classify the injury extent of liver. Serum ALT and AST levels were detected to evaluate the changes of liver enzyme. Results COX-2 protein expression detected by immunohistochemistry in orthotropic liver transplantation group mainly distributed in the district of liver sinusoidal endothelial cells, liver cells and macrophage cells, which was significantly higher than control group and nimesulide intervention group. Expressions of IP mRNA, TP mRNA and COX-2 mRNA in the orthotropic liver transplantation group were significantly increased than those in control group (P＜0.05), and the ratio of IP/TP increased (P＜0.05). Expressions of IP mRNA and TP mRNA in nimesulide intervention group were significantly lower than that in the orthotropic liver transplantation group at 6 h and 12 h after operation (P＜0.05), and the ratio of IP/TP decreased at 3 h, 6 h and 24 h after operation (P＜0.05). The expression of COX-2 mRNA in nimesulide intervention group was significantly lower than that in the orthotropic liver transplantation group at 6 h, 12 h and 24 h after operation. In orthotropic liver transplantation group liver injury was obvious by HE staining, and more severve than that in nimesulide intervention group. Serum AST (each time) and ALT (3 h, 6 h and 12 h) levels in the orthotropic liver transplantation group were significantly higher than that in control group and nimesulide intervention group (P＜0.05) and peaked at 6 h after operation. Conclusion The balance of IP/TP takes part in and plays an important role in the ischemia reperfusion injury of liver transplantation. Changing imbalance of IP/TP may reduce liver transplantation ischemia reperfusion injury by inhibiting COX-2 expression.
ObjectiveTo investigate the expression of keratinocyte growth factor (KGF) and cyclooxygen-ase-2 (COX-2) protein and microvessel density (MVD), and to explore their function and mechanism in the multistep process of gastric cancer. MethodsThe expressions of KGF and COX-2 protein in 64 samples of gastric cancer and 30 cases of normal gastric mucosa tissues were detected by immunohistochemistry. The MVD was detected by staining the endothelial cells in microvessles using anti-CD34 antibody. ResultsThe positive rate of KGF and COX-2 protein expression in gastric cancer were 65.6% (42/64) and 79.7% (51/64), respectively, which was significantly higher than that in normal gastric mucosa tissues 〔(23.3%, 7/30), P=0.046; (13.3%, 4/30), P=0.008〕. The MVD of gastric cancer was 31.8±8.0, which was significantly higher than that of normal gastric mucosa tissues (14.3±6.1), P=0.000. The MVD in gastric cancer with coexpressive KGF and COX-2 protein was 35.9±5.7, which was significant higher than that with non-coexpressive KGF and COX-2 protein (25.7±7.0), P=0.000. Both the expression of KGF and COX-2 protein were related to the invasion of serosa, lymph node metastasis and TNM staging (Plt;0.05, Plt;0.01). The MVD of gastric cancer tissues was related to lymph node metastasis and TNM staging (Plt;0.05), but unrelated to patient’s age, gender, and differentiation of tumor (Pgt;0.05). The co-expression of KGF and COX-2 protein was frequently found in patients with deeper invasion of serosa, lymph node metastasis, and higher TNM staging (Plt;0.05), but which was not associated withpatient’sage, gender, and differentiation of tumor (Pgt;0.05). The expression of KGF protein was positively correlated to the expression of COX-2 protein (r=0.610, P=0.000). There was positive correlation between MVD and the expression of KGF (r=0.675, P=0.000) and COX-2 protein (r=0.657, P=0.000) in gastric cancer, respectively. ConclusionKGF and COX-2 highly expressed by gastric cancer, which may be involved in the invasion and metastasis of gastric cancer by synergisticly promoting the angiogenesis.
【Abstract】Objective To investigate the effects of selective cyclooxygenase-2 (COX-2) inhibitor nimesulide on the proliferation of colon adenocarcinoma cells in vitro and the expression of matrix metalloproteinase-2 (MMP-2). Methods The human colon cancer cell lines HT-29 and HCT-116 were employed in the study, grouped as nimesulide group, DMSO control group and blank control group. After treatment with nimesulide, the inhibitory effect of nimesulide on the proliferation of cancer cells was quantified by MTT assay, and the expression of MMP-2 in the cells was detected by quantitative zymography. Results Nimesulide inhibited the proliferation of HT-29 and HCT-116 cells in time and dosedependent manners. The inhibitory effect on HT-29 cells was ber than that on HCT-116 cells. Nimesulide downregulated the MMP-2 expression in HT-29 cells, whereas the expression in HCT-116 cells remained unchanged. Conclusion Nimesulide can obviously inhibit the growth of colon cancer HT-29 cells with positive COX-2 protein, suggesting that nimesulide may downregulate the expression of MMP-2 by inhibiting the activity of COX-2.
【Abstract】 Objective To study the expressions of cyclooxygenase-2 (Cox-2) and angiopoietin-2 (Ang-2) in colorectal cancer tissues, cancer adjacent tissues and normal colorectal tissues, and the relationship between these expressions and the clinicopathologic features of colorectal cancer. Methods Forty-five excised samples of colorectal adenocarcinoma were confirmed pathologically and 39 of them were of well or moderately differentiated and 6 of poorly differentiated. Lymph nodes metastasis developed in 30 patients. And 15 cases were in stage of A or B and the rest were in the stage of C or D according to the Dukes stage. Taken PBS as the negative control and the verified Cox-2 or Ang-2 positive sections as positive controls, this study detected the expressions of Cox-2 and Ang-2 protein in 45 colorectal cancer tissues, 45 cancer adjacent tissues and 15 normal colorectal tissues by using immunohistochemical SP technique method. Results Cox-2 and Ang-2 were expressed in colorectal cancer tissues and cancer adjacent tissues, but were not expressed in normal colorectal tissues. In 45 colorectal cancer tissues, the positive expression rates of Cox-2 and Ang-2 were 80.0% and 66.7%; in 45 cancer adjacent tissues, the positive expression rates of Cox-2 and Ang-2 were 35.6% and 11.1%, respectively. The positive expression rates of both Cox-2 and Ang-2 in colorectal cancer tissues were significantly higher than those in cancer adjacent and normal colorectal tissues. There were close correlations between the expressions of Cox-2 and Ang-2 and some pathologic features, such as lymph node metastasis and Dukes stage; whereas there were no significant association between the expressions and gender, histological type and position of tumor. There was also a close correlation between the expressions of Cox-2 and Ang-2 themselves. Conclusion Cox-2 and Ang-2 play an important role in the occurrence and development of colorectal cancer. The use of specific inhibitor of Cox-2 as a treatment for colorectal cancer may become feasible and necessary.
ObjectiveTo investigate the expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in human pancreatic adenocarcinoma and their correlation with clinicobiological behavior.MethodsThe expression of COX-2 and VEGF in 51 cases of human pancreatic ductal adenocarcinoma were detected with immunohistochemistry of Envision.ResultsExpression of COX-2 and VEGF in pancreatic ductal adenocarcinoma were 74.5% and 68.6%, respectively; no expression of COX-2 and VEGF in adjacent normal tissue was detected. Both COX-2 and VEGF expression in clinical stage Ⅲ-Ⅳ were much higher than those in clinical stage Ⅰ-Ⅱ, and also higher in positive group of lymph node metastasis than in negative group as well (Plt;0.05). None of them had relation with histological grades, age, sex, tumor size and location. The expression of COX-2 was closely correlated with VEGF (r=0.411, Plt;0.01).ConclusionCOX-2 and VEGF may play a pivotal role in tumorigenesis and tumor progression in pancreatic cancer, they may provide new targets for therapy of pancreatic cancer.
Objective To investigate the effect of inducible nitric oxide synth ase (iNOS) or cyclooxygenase－2 (COX－2) on retinal neovascularization and its possible mechanism in oxygen－induced retinopathy （OIR） mouse model. Methods Retinal neovascularization was induced by oxygen with different concentration. The expression of iNOS, COX－2, matrix metalloproteinases 2 (MMP－2) and vascular end othelial growth factor (VEGF) in the retinae of experimental animals were analyzed by immunohistochemistry, realtime polymerase chain reaction and western blotting technologies. Results The inhibition of COX－2 or iNOS obviously attenuated retinal neovascularization and decreased the expression of VEGF and MMP－2. The iNOS inhibition decreased COX－2 expression, and vice versa. Conclusions COX－2 and iNOS may play a role in retinal neovascularization in OIR mouse model, which may act by regulating the expression of VEGF and MMP－2.
Objective To summarize the research progress in antitumor mechanism of non-steroidal anti-inflam-matory drugs. Methods The domestic and international published literatures about antitumor mechanism of non-steroidal anti-inflammatory drugs in recent years were reviewed. Results The antitumor mechanism of non-steroidal anti-inflam-matory drugs was multistrata and multidigit. Conclusion Non-steroidal anti-inflammatory drugs can be used to prevent the development of colorectal cancer and also be a adjuvant therapy after radical operation for colorectal cancer.
【Abstract】ObjectiveTo investigate the effects of nimesulide, a selective cyclooxygenase-2 (COX-2) inhibitor, on human cholangiocarcinoma QBC939 cell line in vitro. MethodsThe effects of nimesulide on QBC939 cells were observed with the following techniques: the influence of nimesulide on the proliferation of QBC939 cells was determined by MTT assay; the apoptosis of QBC939 cells was viewed and measured by transmission electron microscopy and flow cytometry, respectively; the expressions of proliferation cell nuclear antigen (PCNA) and COX-2 of cholangiocarcinoma cells were detected by immunocytochemistry. ResultsNimesulide inhibited the expressions of PCNA and COX-2 and the proliferation of cholangiocarcinoma QBC939 cells, whose effects intensified as the dose increased and time elongated. Flow cytometry showed that the apoptotic rates of QBC939 cells increased significantly as the dose of nimesulide increased. The typical morphologic features of apoptosis were also observed by transmission electron microscopy. ConclusionNimesulide significantly inhibits the proliferation of QBC939 cells in vitro by inducting cell apoptosis, which may be associated with the downregulation of COX-2 expression, and it also presents the features of dose and time dependents.
Objective To investigate the effects of celecoxib-poly lactide-co-glycolide microparticles (CEL-PLGA-MS) on rat retina after intravitreal injection. Methods A total of 32 male Brown Norway rats were randomly divided into CEL-PLGA-MS group and celecoxib group, 16 rats in each group. The rats in CEL-PLGA-MS group were divided into four dosage group, four rats in each group, which received intravitreal injection of PLGA with celecoxib at the concentration of 40, 80, 160, 320 mu;mol/L, respectively. The rats in celecoxib group were divided into four dosage group, four rats in each group, which received intravitreal injection of celecoxib at the concentration of 40, 80, 160, 320 mu;mol/L, respectively. Phosphate buffer solution (PBS) was injected in two rats as PBS control group. Two rats as normal control group received no treatment. The difference of retinal thickness among groups was measured by optical coherence tomography (OCT). The morphological and histological change of retina was evaluated under light microscope and transmission electron microscope. Results There was no difference of retinal thickness between normal control group and PBS control group (F=0.12,P＞0.05). At the first week after injection, the retinal thickness of CEL-PLGA-MS group and celecoxib group were thicker than that in normal control group and PBS control group (F=9.62, 46.13;P＜0.01). The retinal thickness of celecoxib group was thicker than that in CEL-PLGA-MS group (F=165.15,P＜0.01). The retinal thickness was estimated equal among 40, 80, 320 mu;mol/L dosage groups in CEL-PLGA-MS group (F=4.79,P＜0.01). The retinal thickness of 160, 320 mu;mol/L dosage group were thicker than that in 40, 80 mu;mol/L dosage group in celecoxib group (F=28.10,P＜0.01). At the second week after injection, there was no difference of retinal thickness between CEL-PLGA-MS and celecoxib group (F=3.79,P＞0.05); the retinal thickness of CEL-PLGA-MS and celecoxib group became thinner gradually compare to the first week after injection (F=7.28, 103.99; P＜0.01). At the fourth week after injection, the retinal thickness of celecoxib group was thicker than that in CEL-PLGA-MS group (F=19.11,P＜0.01). The retinal thickness of CEL-PLGA-MS group was approximately the same to normal control group and PBS control group (F=2.02,P＞0.05). The retinal thickness of celecoxib group was thicker than that in normal control group and PBS control group. No considerable abnormality of the retina was seen by light microscope and the retinal thickness corresponded with the values measured by OCT at the first week after injection. The abnormal structures of the retina were seen in 160, 320 mu;mol/L dosage group of celecoxib group and inner changed evidently by the transmission electron microscope. Disordered arrangement of microfilaments, dilated microtubule and some mitochondria vacuolation were observed in 320mu;mol/L dosage group of celecoxib group. Others changed slightly. Conclusions CEL-PLGA-MS has less toxicity on the retina than free-celecoxib after intravitreal injection. The safety of intravitreal injection with CEL-PLGA-MS is better than celecoxib.
Objective To evaluate the potential roles of celecoxib on proliferation and cell cycle progression of colon adenocarcinoma cells and on the hepatic metastasis of nude mice. Methods The human colon cancer cells HT-29 and HCT-116 were employed in the study. After treatment with celecoxib, the inhibitory effects of celecoxib on the proliferation of cancer cells were quantified by MTT assay, and the cell cycle progression was detected by flow cytometry, tumor cells were inoculated in nude mice, and the hepatic metastasis was detected. Results ①Celecoxib inhibited the proliferation of the tumor cells in time and dose-dependent manners （P＜0.05，P＜0.01）. The inhibitory effect on HT-29 cells was ber than that on HCT-116 cells （P＜0.05）. ②Celecoxib changed cell cycle progression of both kinds of cells, and decreased the proliferation index of both kinds of cells too. ③Celecoxib could inhibit the growth of the hepatic metastatic tumor obviously. Conclusion Celecoxib may inhibit the activity of cyclooxygenase-2, and resulting in the inhibition of division and proliferation, apoptosis of tumor cells and interfering in metastasis and relapse of colon cancer.