AIM: To construct a stable transfectant of human liver carcinoma cell line SMMC7721 that could secret human endostatin and to explore the effect of human endostatin expressed by the transfectant on endothelial cell pr...AIM: To construct a stable transfectant of human liver carcinoma cell line SMMC7721 that could secret human endostatin and to explore the effect of human endostatin expressed by the transfectant on endothelial cell proliferation. METHODS: Recombinant retroviral plasmid pLncx-Endo containing the cDNA for human endostatin gene together with rat albumin signal peptide was engineered and transferred into SMMC7721 cell by lipofectamine. After selection with G418, endostatin-transfected SMMC7721 cells were chosen and expanded. Immunohistochemical staining and Western blot were used to detect the expression of human endostatin in transfected SMMC7721 cells and its medium. The conditioned medium of endostatin-transfected and control SMMC7721 cells were collected to cultivate with human umbilical vein endothelial cells for 72 hours. The inhibitory effect of endostatin, expressed by transfected SMMC7721 cells, on endothelial proliferation in vitro was observed by using MTT assay. RESULTS: A 550 bp specific fragment of endostatin gene was detected from the PCR product of endostatin-transfected SMMC7721 cells. Immunohistochemistry and Western blot analysis confirmed the expression and secretion of foreign human endostatin protein by endostatin-transfected SMMC7721 cells. In vitro endothelial proliferation assay showed that 72 hours after cultivation with human umbilical vein endothelial cells, the optical density (OD) in group using the medium from endostatin-transfected SMMC7721 cells was 0.51 +/- 0.06, lower than that from RPMI 1640 group (0.98 +/- 0.09) or that from control plasmid pLncx-transfected SMMC7721 cells (0.88 +/- 0.11). The inhibitory rate for medium from endostatin-transfected SMMC7721 cells was 48%, significantly higher than that from empty plasmid pLncx-transfected SMMC7721 cells (10.2%, P【0.01). CONCLUSION: Human endostatin can be stably expressed by SMMC7721 cell transferred with human endostatin gene and its product can significantly inhibit the proliferation of human umbilical vein endothelial cell in vitro.展开更多
AIM:To investigate the antiangiogenic effects of endostatin on colonic carcinoma cell line implanted in nude mice and its mechanism. METHODS:Nude mice underwent subcutaneous injection with LS-174t colonic carcinoma ce...AIM:To investigate the antiangiogenic effects of endostatin on colonic carcinoma cell line implanted in nude mice and its mechanism. METHODS:Nude mice underwent subcutaneous injection with LS-174t colonic carcinoma cell line to generate carcinoma and were randomly separated into two groups.Mice received injection of vehicle or endostatin every day for two weeks. After the tumor was harvested,the tumor volumes were determined,and the expressions of CD34,VEGF and FIk-1 were examined by immunohistochemical method. RESULTS:Tumor volume was significantly inhibited in the endostatin group(84.17%)and tumor weight was significantly inhibited in the endostatin group(0.197±0.049) compared to the control group(1.198±0.105)(F=22.56, P=0.001),microvessel density(MVD)was significantly decreased in the treated group(31.857±3.515)compared to the control group(100.143±4.290)(F=151.62,P<0.001). Furthermore,the expression of FIk-1 was significantly inhibited in the treated group(34.29%) ompared to the control group(8.57%)(X^2=13.745,P=0.001).However no significant decrease was observed in the expression of vascular endothelial growth factor(VEGF)between these two groups(X^2=0.119,P=0.730). CONCLUSION:Endostatin can inhibit tumor growth and angiogenesis by blocking Vegf/FIk-1 pathway.This experiment provides the theory basis for developing a new anti-carcinoma drug through studying the properties of anti-angiogenesis inhibitors.展开更多
文摘AIM: To construct a stable transfectant of human liver carcinoma cell line SMMC7721 that could secret human endostatin and to explore the effect of human endostatin expressed by the transfectant on endothelial cell proliferation. METHODS: Recombinant retroviral plasmid pLncx-Endo containing the cDNA for human endostatin gene together with rat albumin signal peptide was engineered and transferred into SMMC7721 cell by lipofectamine. After selection with G418, endostatin-transfected SMMC7721 cells were chosen and expanded. Immunohistochemical staining and Western blot were used to detect the expression of human endostatin in transfected SMMC7721 cells and its medium. The conditioned medium of endostatin-transfected and control SMMC7721 cells were collected to cultivate with human umbilical vein endothelial cells for 72 hours. The inhibitory effect of endostatin, expressed by transfected SMMC7721 cells, on endothelial proliferation in vitro was observed by using MTT assay. RESULTS: A 550 bp specific fragment of endostatin gene was detected from the PCR product of endostatin-transfected SMMC7721 cells. Immunohistochemistry and Western blot analysis confirmed the expression and secretion of foreign human endostatin protein by endostatin-transfected SMMC7721 cells. In vitro endothelial proliferation assay showed that 72 hours after cultivation with human umbilical vein endothelial cells, the optical density (OD) in group using the medium from endostatin-transfected SMMC7721 cells was 0.51 +/- 0.06, lower than that from RPMI 1640 group (0.98 +/- 0.09) or that from control plasmid pLncx-transfected SMMC7721 cells (0.88 +/- 0.11). The inhibitory rate for medium from endostatin-transfected SMMC7721 cells was 48%, significantly higher than that from empty plasmid pLncx-transfected SMMC7721 cells (10.2%, P【0.01). CONCLUSION: Human endostatin can be stably expressed by SMMC7721 cell transferred with human endostatin gene and its product can significantly inhibit the proliferation of human umbilical vein endothelial cell in vitro.
基金Supported by the Key Technologies Research and Development Program of Heilongjiang Province During the 9th Five-Year Plan Period,No.G99C 19-5
文摘AIM:To investigate the antiangiogenic effects of endostatin on colonic carcinoma cell line implanted in nude mice and its mechanism. METHODS:Nude mice underwent subcutaneous injection with LS-174t colonic carcinoma cell line to generate carcinoma and were randomly separated into two groups.Mice received injection of vehicle or endostatin every day for two weeks. After the tumor was harvested,the tumor volumes were determined,and the expressions of CD34,VEGF and FIk-1 were examined by immunohistochemical method. RESULTS:Tumor volume was significantly inhibited in the endostatin group(84.17%)and tumor weight was significantly inhibited in the endostatin group(0.197±0.049) compared to the control group(1.198±0.105)(F=22.56, P=0.001),microvessel density(MVD)was significantly decreased in the treated group(31.857±3.515)compared to the control group(100.143±4.290)(F=151.62,P<0.001). Furthermore,the expression of FIk-1 was significantly inhibited in the treated group(34.29%) ompared to the control group(8.57%)(X^2=13.745,P=0.001).However no significant decrease was observed in the expression of vascular endothelial growth factor(VEGF)between these two groups(X^2=0.119,P=0.730). CONCLUSION:Endostatin can inhibit tumor growth and angiogenesis by blocking Vegf/FIk-1 pathway.This experiment provides the theory basis for developing a new anti-carcinoma drug through studying the properties of anti-angiogenesis inhibitors.
