中文摘要：

目的探讨LGR5在4个肝癌细胞系、癌旁组织及肝癌组织中的表达，及在肝癌中的作用。方法免疫印迹法及实时定量RT—PCR检测正常细胞和4种肝癌细胞中LGR5的表达；采用免疫组织化学检测36例肝癌及癌旁组织中LGR5及β—catenin的表达；利用免疫细胞化学检测HepG2细胞中LGR5的表达。结果免疫印迹法及实时定量RT-PCR证实，与正常肝脏细胞相比，LGR5除了在HepG2细胞中等表达外，在另外3种肝癌细胞Hep3B、Huh7、PLC中呈弱表达或不表达（P〈0．05），免疫细胞化学结果进一步证实LGR5在HepG2细胞膜上表达。免疫组织化学结果显示，与癌旁组织相比，LGR5在肝癌组织中表达明显减少，而β—catenin的表达显著增加。结论与正常肝脏细胞及癌旁组织相比，LGR5在多种肝癌细胞及肝癌组织中的表达明显减少。

英文摘要：

Objective To investigate the expression of LGR5 in human hepatocelluar cancer tissues and four human liver cancer cell lines and to evaluate its value in the development of hepatoeellular cancer. Methods The mRNA and protein expression of LGR5 in human liver cancer cell lines and normal liver cell were detected by real-time PCR and Western blotting. Expression of LGR5 and β-catenin in hepatocellular cancer tissue was determined by immunohistochemistry. LGR5 localization and expression in HepG2 ceils were tested by immunocytochemical staining. Results Western blotting and real-time PCR results demonstrated that the expression of LGR5 decreased significantly in HepG2, Hep3B, Huh7 and PLC cells compared to LO2 cells（ P 〈 0. 05 ）. Immunuhistochemistry results also showed that LGR5 was downregulated in cancer tissue compared to adjacent tumor tissue, whereas β-catenin expression was upregulated in cancer tissue. Conclusion Compared to adjacent tumor tissue and normal liver ceils, LGR5 expression was significantly downregulated in 36 cases of hepatocelluar cancer tissues and four kinds of hepatocelluar cancer cell line.