氯沙坦通过AT1R/VEGF 信号通路对 肝癌血管生成的影响

Losartan attenuates angiogenesis in hepatocellular carcinoma via down-regulation of AT1R/VEGF signaling pathway

摘要:

目的 探讨氯沙坦是否通过下调血管紧张素Ⅱ 1 型受体（AT1R）/ 血管内皮生长因子（VEGF） 信号通路，抑制肝癌细胞的血管生成。方法 采用免疫荧光染色和Western blot 检测AT1R 在肝癌细胞系 HepG2、HuH-7 和PLC/PRF/5，以及正常肝细胞LO2 中的表达。采用Western blot 检测氯沙坦对肝癌细胞 系HepG2 中AT1R 表达的影响，酶联免疫吸附法（ELISA）检测氯沙坦对肝癌细胞系HepG2 中VEGF 的影响。 采用免疫组织化学法检测氯沙坦对大鼠肝癌组织中AT1R、VEGF 和CD34 表达的影响。结果 AT1R 在正 常肝细胞LO2 中低表达（P <0.05），在肝癌细胞系HepG2、HuH-7 和PLC/PRF/5 中高表达（P <0.05），在 HepG2 细胞中表达最高（P <0.05）。在肝癌细胞系HepG2 中加入氯沙坦后，AT1R 蛋白水平和VEGF 浓度降 低（P <0.05）。大鼠肝癌组织中AT1R、VEGF 和CD34 高表达，而加入氯沙坦后，AT1R、VEGF 和CD34 表 达降低（P <0.05）。结论 氯沙坦通过抑制AT1R/VEGF 信号通路，可以阻碍肝癌血管的生成。

Abstract:

Objective To investigate the effect of Losartan on angiogenesis in hepatocellular carcinoma and angiotensin II receptor 1 (AT1R)/vascular endothelial growth factor (VEGF) pathway. Methods Immunofluorescent staining and Western blot were used to detect the expression levels of AT1R in hepatocellular carcinoma cell lines HepG2, HuH-7 and PLC/PRF/5, and normal hepatocytes LO2. In HepG2 cells, Western blot was used to test the variation of AT1R expression level that was influenced by Losartan and then ELISA was used to investigate the change of VEGF level after treatment by Losartan. And immunohistochemistry was used to study the expression levels of AT1R, VEGF and CD34 in hepatocellular carcinoma tissues of rats that were influenced by Losartan. Results The results of immunofluorescent staining and Western blot showed the expression level of AT1R was low in LO2 cells (P < 0.05), but was high in hepatocellular carcinoma cell lines HepG2, HuH-7 and PLC/PRF/5 cells (P < 0.05), and the highest in HepG2 cells (P < 0.05). After addition of Losartan in HepG2 cells, the protein levels of AT1R and VEGF were decreased (P < 0.05). The expression levels of AT1R, VEGF and CD34 were high in liver cancer tissues, but decreased after addition of Losartan (P < 0.05). Conclusions Losartan attenuates angiogenesis in hepatocellular carcinoma via down-regulation of AT1R/VEGF signaling pathway.