CTGF在胃癌中的表达及其促进血管生成的机制

Expressions of connective tissue growth factor in gastric cancer and its mechanism of angiogenesis

目的研究CTGF在人胃癌标本中表达情况及其促进血管生成的机制。方法应用Real Time PCR和免疫组织化学染色检测胃癌标本中CTGF mRNA,VEGF mRNA及其在组织中蛋白表达情况;应用pcDNA3.1质粒上调AGS细胞中CTGF的表达,并用Real Time PCR和Western blot检测VEGF mRNA水平和蛋白水平表达变化;AGS稳定株细胞接种于裸鼠,成瘤后肿瘤组织切片,免疫组化染色。结果与正常组织相比,胃癌组织中CTGF mRNA,VEGF mRNA表达水平均显著增加,免疫组化亦显示CT-GF、VEGF在胃癌的标本中显色比正常对照组织强。统计显示两者mRNA水平及免疫组化表达有相关性(P<0.05)。转染pcD-NA3.1 CTGF质粒后,AGS细胞中CTGF蛋白的表达上调,Real Time PCR及Western blot检测显示过表达CTGF后,VEGF表达上调。与对照细胞相比,过表达CTGF的AGS的肿瘤形成和生成速度明显加快(P<0.05)。免疫组化染色显示VEGF的染色明显强于对照组。结论在胃癌中CTGF,VEGF表达明显增加,CTGF可能通过上调VEGF表达促进肿瘤血管生成。

Objective To observe the expressions of connective tissue growth factor（CTGF） in the samples of gastric cancer（GC） and its mechanism of angiogenesis.Methods The expressions of CTGF mRNA,vascular endothelial growth factor mRNA（VEGF mRNA） were detected by Real-Time PCR and immunohistochemistry in 22 pairs of GC samples.pcDNA3.1 plasmid was used to overexpress CTGF in AGS,meanwhile Real-Time PCR and Western blot were employed to detect the changes in VEGF expressions.Nude mice were inoculated against AGS cell lines and sections were made after tumor formed.The angiogenesis was determined by immunohistochemistry.Results The expressions of CTGF mRNA and VEGF mRNA in GC were significantly increased compared with the controls.CTGF and VEGF positive rates in cancerous tissues were much higher than those in normal tissues.Statistical analysis showed that there were correlations between the expressions and mRNA levels of CTGF and VEGF（P〈0.05）.CTGF expressions were efficiently enhanced after transfecting pcDNA3.1 CTGF practicles.The results of Real Time PCR and Western Blot suggested that the expressions of VEGF were increased in CTGF-transfected stable cell AGS.The tumors were developed with shorter latency as well as larger size in AGS/CTGF cells compared with those in control group（P〈0.05）.VEGF positive staining in tumors formed from AGS/CTGF cells was more intense than those formed form control cells.Conclusion The expressions of CTGF and VEGF were up-regulated in gastric carcinoma.CTGF can promote the angiogenesis through up-regulation of VEGF.