INTRODUCTIONHepatocellular carcinoma(HCC)is one of the major causes of death in the word.The mechanism of carcinogenesis is unknown,although it is widely accepted that HBV and HCV are clsely related to liver cancer[1-...INTRODUCTIONHepatocellular carcinoma(HCC)is one of the major causes of death in the word.The mechanism of carcinogenesis is unknown,although it is widely accepted that HBV and HCV are clsely related to liver cancer[1-5[1-5].Previously,a variety of studies have described the differences in gene expression which distinguished tumor from nontumor[6-11].Cloning of the genes,especially the genes associated with HBV and HCV,is still very important to account for the development of liver cancer.展开更多
AIM: To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesis of human gastric carcinoma more directly. METHODS: The expression of VEGF and its receptor kinase-domain insert containing rec...AIM: To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesis of human gastric carcinoma more directly. METHODS: The expression of VEGF and its receptor kinase-domain insert containing receptor (KDR) in human gastric cancer tissue were observed by immunohistochemical staining. VEGF levels were manipulated in human gastric cancer cell using eukaryotic expression constructs designed to express the complete VEGF(165) complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or down-regulated. RESULTS: VEGF-positive rate was 50%, and VEGF was mainly localized in the cytoplasm and membrane of the tumor cells, while KDR was mainly located in the membrane of vascular endothelial cells in gastric cancer tissues and peri-cancerous tissue. In 2 cases of 50 specimens, the gastric cancer cells expressed KDR, localized in both the cytoplasm and membrane. Introduction of VEGF(165) antisense into human gastric cancer cells (SGC-7901, immunofluorescence intensity, 31.6%)) resulted in a significant reduction in VEGF-specific messenger RNA and total and cell surface VEGF protein (immunofluorescence intensity, 8.9%) (P【0.05). Conversely, stable integration of VEGF(165) in the sense orientation resulted in an increase in cellular and cell surface VEGF (immunofluorescence intensity, 75.4%) (P【0.05). Lowered VEGF levels were associated with a marked decrease in the growth of nude mouse xenografted tumor (at 33 days postimplantation, tumor volume: 345.40 +/- 136.31 mm3)(P【0.05 vs control SGC-7901 group: 1534.40 +/- 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tumor volume: 2350.50 +/- 637.70 mm3) (P【0.05 vs control SGC-7901 group). CONCLUSION: This study provides direct evidence that VEGF plays an important role in the oncogenesis of human gastric cancer.展开更多
目的 :构建双亚基共表达鼠白细胞介素 - 12 (m IL- 12 )真核表达质粒 ,并观察其在体内外的表达。方法 :将m IL - 12 p35和 p4 0全长编码 c DNA构建在 pc DN A 3.1载体上 ,然后把 p35表达单元 (CMV- p35 - BGH PA)插入pc DNA 3.1/ p4 0载...目的 :构建双亚基共表达鼠白细胞介素 - 12 (m IL- 12 )真核表达质粒 ,并观察其在体内外的表达。方法 :将m IL - 12 p35和 p4 0全长编码 c DNA构建在 pc DN A 3.1载体上 ,然后把 p35表达单元 (CMV- p35 - BGH PA)插入pc DNA 3.1/ p4 0载体 ,使两个目的基因均受各自的启动子 CMV控制 ,构建成 m IL - 12双亚基共表达质粒 p Cm IL -12 ,并进行体内外表达。结果 :p Cm IL - 12在体外转染 COS- 7细胞后 ,经 EL ISA证实有 m IL- 12表达 ,其表达上清能在体外明显增强小鼠 NK细胞活性。小鼠皮内注射 p Cm IL - 12亦能增强小鼠 NK细胞活性。结论 :所构建的质粒在体内外均能表达有生物学活性的 m IL-展开更多
文摘INTRODUCTIONHepatocellular carcinoma(HCC)is one of the major causes of death in the word.The mechanism of carcinogenesis is unknown,although it is widely accepted that HBV and HCV are clsely related to liver cancer[1-5[1-5].Previously,a variety of studies have described the differences in gene expression which distinguished tumor from nontumor[6-11].Cloning of the genes,especially the genes associated with HBV and HCV,is still very important to account for the development of liver cancer.
文摘AIM: To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesis of human gastric carcinoma more directly. METHODS: The expression of VEGF and its receptor kinase-domain insert containing receptor (KDR) in human gastric cancer tissue were observed by immunohistochemical staining. VEGF levels were manipulated in human gastric cancer cell using eukaryotic expression constructs designed to express the complete VEGF(165) complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or down-regulated. RESULTS: VEGF-positive rate was 50%, and VEGF was mainly localized in the cytoplasm and membrane of the tumor cells, while KDR was mainly located in the membrane of vascular endothelial cells in gastric cancer tissues and peri-cancerous tissue. In 2 cases of 50 specimens, the gastric cancer cells expressed KDR, localized in both the cytoplasm and membrane. Introduction of VEGF(165) antisense into human gastric cancer cells (SGC-7901, immunofluorescence intensity, 31.6%)) resulted in a significant reduction in VEGF-specific messenger RNA and total and cell surface VEGF protein (immunofluorescence intensity, 8.9%) (P【0.05). Conversely, stable integration of VEGF(165) in the sense orientation resulted in an increase in cellular and cell surface VEGF (immunofluorescence intensity, 75.4%) (P【0.05). Lowered VEGF levels were associated with a marked decrease in the growth of nude mouse xenografted tumor (at 33 days postimplantation, tumor volume: 345.40 +/- 136.31 mm3)(P【0.05 vs control SGC-7901 group: 1534.40 +/- 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tumor volume: 2350.50 +/- 637.70 mm3) (P【0.05 vs control SGC-7901 group). CONCLUSION: This study provides direct evidence that VEGF plays an important role in the oncogenesis of human gastric cancer.
文摘目的 :构建双亚基共表达鼠白细胞介素 - 12 (m IL- 12 )真核表达质粒 ,并观察其在体内外的表达。方法 :将m IL - 12 p35和 p4 0全长编码 c DNA构建在 pc DN A 3.1载体上 ,然后把 p35表达单元 (CMV- p35 - BGH PA)插入pc DNA 3.1/ p4 0载体 ,使两个目的基因均受各自的启动子 CMV控制 ,构建成 m IL - 12双亚基共表达质粒 p Cm IL -12 ,并进行体内外表达。结果 :p Cm IL - 12在体外转染 COS- 7细胞后 ,经 EL ISA证实有 m IL- 12表达 ,其表达上清能在体外明显增强小鼠 NK细胞活性。小鼠皮内注射 p Cm IL - 12亦能增强小鼠 NK细胞活性。结论 :所构建的质粒在体内外均能表达有生物学活性的 m IL-
