AIM: To examine the effects of Helicobacter pylori(Hpylori) infection on the invasiveness of gastric cancer cells,and to elucidate its mechanism. METHODS: Gastric carcinoma cells, MKN-45, were incubated with CagA-posi...AIM: To examine the effects of Helicobacter pylori(Hpylori) infection on the invasiveness of gastric cancer cells,and to elucidate its mechanism. METHODS: Gastric carcinoma cells, MKN-45, were incubated with CagA-positive H pylori, and cell invasion was determined by Matrigel analysis.The expression of matrix metallopr-oteinase-9 (MMP-9),vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) were assessed by Western-blot analysis, and transcriptional activation of the COX-2 promoter was examined by measuring luciferase and β-galactosidase activities. Lastly,the proteinDNA interaction was confirmed by an electrophoretic mobility shift assay. RESULTS: The current studies showed that: (1) incubation of CagA-positive H pylori with MKN-45 cells significantly promotes gastric cancer cells invasion, and this effect is attenuated by pre-treatment with NS-398, a COX-2 inhibitor, or PDTC,a nuclear factor κB (NF-κB) inhibitor;(2) the induction of MKN-45 cells invasion by Hpylori is associated with increases in COX-2, MMP-9, and VEGF protein expression, and co-incubation of NS-398 or PDTC significantly reduces these effects;(3) H pylori infection transactivates COX-2 promoter activity and increases the binding of NF-κB to this promoter. CONCLUSION: Our data demonstrate that H pylori infection promotes gastric epithelial cells invasion by activating MMP-9 and VEGF expression. These effects appear to be mediated through a NF-κB and COX-2 mediated pathway, as COX-2 or NF-κB inhibitor significantly attenuate the invasiveness of gastric cancer cells and the expressions of MMP-9 and VEGF protein.展开更多
AIM： To examine matrix metalloproteinase-2 （MMP-2） expression in gastric cancer tissues and to evaluate its relationship with lymph node micrometastasis. MATERIALS： The authors studied 850 lymph nodes resected fro...AIM： To examine matrix metalloproteinase-2 （MMP-2） expression in gastric cancer tissues and to evaluate its relationship with lymph node micrometastasis. MATERIALS： The authors studied 850 lymph nodes resected from 30 patients with gastric carcinoma who underwent gastrectomy with lymphadenetomy using reverse transcription polymerase chain reaction （RT-PCR） assay in addition to H-E staining. MMP-2 expression of the tumor tissues was detected by immunohistochemical technique （EliVision^TM plus）. RESULTS： MMP-2 expression was positive in 21 （70%） cases and negative in g （30%） cases. No significant correlations were found between MMP-2 expression and other variables such as age, gender, tumor location, tumor diameter, Lauren classification and lymphatic invasion. In contrast, MMP-2 expression correlated significantly with depth of tumor infiltration （P = 0.022）, lymph node metastasis （P = 0.030） and tumor differentiation （P = 0.043）. Lymph node micrometastases were detected in 77 （12.5%） lymph nodes of 14 （46.7%） gastric carcinoma patients. MMP-2 expression was positive in 12 （85.7%） of the 14 patients with lymph node micrometastasis, and in g （56.3%） of the 16 patients without lymph node micrometastasis （P = 0.118）. CONCLUSIONS： Our results demonstrate that MMP-2 expression has significant correlation with tumor invasion, tumor differentiation and lymph node metastases. MMP-2 expression may be an important biological characteristics and significant prognostic parameter of gastric carcinoma. We also conclude that MMP-2 may participate in the development of lymph node micrometastasis of gastric carcinoma. Further investigations are needed to draw a conclusion.展开更多
AIM: To investigate the expression of matrix metallopr-oteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10 (IL-10). METHODS: Hepatic fibro...AIM: To investigate the expression of matrix metallopr-oteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10 (IL-10). METHODS: Hepatic fibrosis was induced by CCI4 administration and 60 male Sprague-Dawley rats were randomly divided into normal control group (group N, 8 rats), CCI4-induced group (group C, 28 rats) and IL-10-treated group (group I, 24 rats). At the beginning of the 7th and 11th wk, rats in each group were routinely perfused with pronase E and type IV collagenase through portal vein catheter and the suspension was centrifuged by 11% Nycodenz density gradient to isolate hepatic stellate cells (HSCs). RT-PCR was used to analyze mRNA of MMP-2 and TIMP-1 from freshly isolated cells. Densitometric data were standardized with β-actin signals. Immunocytochemistry was performed to detect MMP-2 and TIMP-1 expression in HSC cultured for 72 h. RESULTS: Compared to group N in the 7th wk, MMP-2 and TIMP-1 mRNA increased in group C (P= 0.001/0.001) and group I (P= 0.001/0.009). The level of MMP-2 and TIMP-1 mRNA in group I was significantly lower than that in group C (P= 0.001/0.001). In the 11th wk, MMP-2 mRNA in group I was still lower than that in group C (P = 0.005), but both dropped compared with that in the 7th week (P = 0.001/0.004). TIMP-1 mRNA in group I was still lower than that in group C (P= 0.001), and increased in group C (P= 0.001) while decreased in group I (P = 0.042) compared with that in the 7th wk. Same results were found by immunocytochemistry. CONCLUSION: Expression of MMP-2 and TIMP-1 is increased in hepatic fibrosis. IL-10 exhibits an antifibrogenic effect by suppressing MMP-2 and TIMP-1 expression.展开更多
基金Supported by the Taichung Veterans General Hospital Research Grant: TCVGH-933308C
文摘AIM: To examine the effects of Helicobacter pylori(Hpylori) infection on the invasiveness of gastric cancer cells,and to elucidate its mechanism. METHODS: Gastric carcinoma cells, MKN-45, were incubated with CagA-positive H pylori, and cell invasion was determined by Matrigel analysis.The expression of matrix metallopr-oteinase-9 (MMP-9),vascular endothelial growth factor (VEGF), and cyclooxygenase-2 (COX-2) were assessed by Western-blot analysis, and transcriptional activation of the COX-2 promoter was examined by measuring luciferase and β-galactosidase activities. Lastly,the proteinDNA interaction was confirmed by an electrophoretic mobility shift assay. RESULTS: The current studies showed that: (1) incubation of CagA-positive H pylori with MKN-45 cells significantly promotes gastric cancer cells invasion, and this effect is attenuated by pre-treatment with NS-398, a COX-2 inhibitor, or PDTC,a nuclear factor κB (NF-κB) inhibitor;(2) the induction of MKN-45 cells invasion by Hpylori is associated with increases in COX-2, MMP-9, and VEGF protein expression, and co-incubation of NS-398 or PDTC significantly reduces these effects;(3) H pylori infection transactivates COX-2 promoter activity and increases the binding of NF-κB to this promoter. CONCLUSION: Our data demonstrate that H pylori infection promotes gastric epithelial cells invasion by activating MMP-9 and VEGF expression. These effects appear to be mediated through a NF-κB and COX-2 mediated pathway, as COX-2 or NF-κB inhibitor significantly attenuate the invasiveness of gastric cancer cells and the expressions of MMP-9 and VEGF protein.
基金Supported by the National Nature Science Foundation of China, No. 30271276
文摘AIM： To examine matrix metalloproteinase-2 （MMP-2） expression in gastric cancer tissues and to evaluate its relationship with lymph node micrometastasis. MATERIALS： The authors studied 850 lymph nodes resected from 30 patients with gastric carcinoma who underwent gastrectomy with lymphadenetomy using reverse transcription polymerase chain reaction （RT-PCR） assay in addition to H-E staining. MMP-2 expression of the tumor tissues was detected by immunohistochemical technique （EliVision^TM plus）. RESULTS： MMP-2 expression was positive in 21 （70%） cases and negative in g （30%） cases. No significant correlations were found between MMP-2 expression and other variables such as age, gender, tumor location, tumor diameter, Lauren classification and lymphatic invasion. In contrast, MMP-2 expression correlated significantly with depth of tumor infiltration （P = 0.022）, lymph node metastasis （P = 0.030） and tumor differentiation （P = 0.043）. Lymph node micrometastases were detected in 77 （12.5%） lymph nodes of 14 （46.7%） gastric carcinoma patients. MMP-2 expression was positive in 12 （85.7%） of the 14 patients with lymph node micrometastasis, and in g （56.3%） of the 16 patients without lymph node micrometastasis （P = 0.118）. CONCLUSIONS： Our results demonstrate that MMP-2 expression has significant correlation with tumor invasion, tumor differentiation and lymph node metastases. MMP-2 expression may be an important biological characteristics and significant prognostic parameter of gastric carcinoma. We also conclude that MMP-2 may participate in the development of lymph node micrometastasis of gastric carcinoma. Further investigations are needed to draw a conclusion.
基金Supported by the Science and Technology Project of Fujian Educational Committee, No. JA04198
文摘AIM: To investigate the expression of matrix metallopr-oteinase-2 and tissue inhibitor of metalloproteinase-1 in hepatic fibrosis and the antifibrogenic role of exogenous interleukin-10 (IL-10). METHODS: Hepatic fibrosis was induced by CCI4 administration and 60 male Sprague-Dawley rats were randomly divided into normal control group (group N, 8 rats), CCI4-induced group (group C, 28 rats) and IL-10-treated group (group I, 24 rats). At the beginning of the 7th and 11th wk, rats in each group were routinely perfused with pronase E and type IV collagenase through portal vein catheter and the suspension was centrifuged by 11% Nycodenz density gradient to isolate hepatic stellate cells (HSCs). RT-PCR was used to analyze mRNA of MMP-2 and TIMP-1 from freshly isolated cells. Densitometric data were standardized with β-actin signals. Immunocytochemistry was performed to detect MMP-2 and TIMP-1 expression in HSC cultured for 72 h. RESULTS: Compared to group N in the 7th wk, MMP-2 and TIMP-1 mRNA increased in group C (P= 0.001/0.001) and group I (P= 0.001/0.009). The level of MMP-2 and TIMP-1 mRNA in group I was significantly lower than that in group C (P= 0.001/0.001). In the 11th wk, MMP-2 mRNA in group I was still lower than that in group C (P = 0.005), but both dropped compared with that in the 7th week (P = 0.001/0.004). TIMP-1 mRNA in group I was still lower than that in group C (P= 0.001), and increased in group C (P= 0.001) while decreased in group I (P = 0.042) compared with that in the 7th wk. Same results were found by immunocytochemistry. CONCLUSION: Expression of MMP-2 and TIMP-1 is increased in hepatic fibrosis. IL-10 exhibits an antifibrogenic effect by suppressing MMP-2 and TIMP-1 expression.
