摘要
AIM： To investigate the effects of mifepristone on the invasive and metastatic potential of human gastric adenocarcinoma cell line MKN-45 and its mechanisms. METHODS: After incubation with various concentrations of mifepristone (5, 10, 20 umol/L), the adhesion to artificial basement membrane, Matrigel, and the migration of MKN-45 cells were assayed using MTT assay and Transwell cell culture chambers, respectively. Enzyme- linked immunoabsorbent assay (ELISA) and flow cytometry were used to determine the expression of vascular endothelial growth factor (VEGF) and integrin 133 in the cells. After subcutaneous transplantation of MKN-45 cells in nude mice, mifepristone (50 mg/kg.d) was administrated subcutaneously for 8 wk to assess its effects on tumor metastasis. Immunohistochemical analysis was used to detect the expression of VEGF and microvascular density (MVD) in xenografted tumors. RESULTS: Mifepristone dose-dependently inhibited the heterotypic adhesion to Matrigel of MKN-45 cells. The inhibition was accompanied by a significant down-regulation of integrin 133 expression in the cells. After incubation with 5, 10, 20 umol/L mifepristone, the number of migrated MKN-45 cells was 72+8, 50+6, 41+5 in experiment group, and 94+16 in control group (P<0.01). Meanwhile, secreted VEGF protein of MKN-45 cells in mifepristone-treated group (14.2+2.9, 8.9+3.1, 5.4+2.1 ng/g per liter) was significantly lower than that in control group (22.7+4.3 ng/g per liter, P<0.01). In vivo, mifepristone decreased the number of metastatic foci in lungs of nude mice and down-regulated the expression of VEGF and MVD in the xenograted tumors. CONCLUSION: Mifepristone can effectively inhibit the invasive and metastatic potential of human gastric adenocarcinoma cell line MKN-45 in vitro and in vivo through inhibition of heterotypic adhesion to basement membrane, cell migration and angiogenesis.
AIM:To investigate the effects of mifepristone on the invasive and metastatic potential of human gastric adenocarcinoma cell line MKN-45 and its mechanisms. METHODS:After incubation with various concentrations of mifepristone(5,10,20 μmol/L),the adhesion to artificial basement membrane,Matrigel,and the migration of MKN-45 cells were assayed using MTT assay and Transwell cell culture chambers,respectively.Enzyme- linked immunoabsorbent assay(ELISA)and flow Oltometry were used to determine the expression of vascular endothelial growth factor(VEGF) and integrin β3 in the cells.After subcutaneous transplantation of MKN-45 cells in nude mice,mifepristone(50 mg/kg·d) was administrated subcutaneously for 8 wk to assess its effects on tumor metastasis,immunohistochemical analysis was used to detect the expression of VEGF and microvascular density(MVD)in xenografted tumors. RESULTS:Mifepristone dose-dependently inhibited the heterotypic adhesion to Matrigel of MKN-45 cells.The inhibition was accompanied by a significant down-regulation of integrin β3 expression in the cells.After incubation with 5,10,20μmol/L mifepristone,the number of migrated MKN- 45 cells was 72±8,50±6,41±5 in experiment group,and 94±16 in control group(P<0.01).Meanwhile,secreted VEGF protein of MKN-45 cells in mifepristone-treated group (14.2±2.9,8.9±3.1,5.4±2.1 ng/g per liter)was significantly lower than that in control group(22.7±4.3 ng/g per liter, P<0.01).In vivo,mifepristone decreased the number of metastatic foci in lungs of nude mice and down-regulated the expression of VEGF and MVD in the xenograted tumors. CONCLUSION:Mifepristone can effectively inhibit the invasive and metastatic potential of human gastric adenocarcinoma cell line MKN-45 in vitro and in vivo through inhibition of heterotypic adhesion to basement membrane, cell migration and angiogenesis.
基金
Supported by the National Key Research Project Foundation of China,No.96-905- 02-01,and the National Natural Science Foundation of China,No.39630340
