肝癌细胞前列腺素E_2受体表达和分布的研究

The expression of four kinds of prostaglandin E_2 receptor and distribution in human liver carcinoma cells

目的:基于肝癌细胞(肝细胞癌细胞和胆管上皮癌细胞)对PGE2的不同反应性,研究Hep3B、HuH7、SG231和HuCCT1肝癌细胞株前列腺素E2受体的表达类型和分布定位。方法:体外培养肝细胞癌细胞株(Hep3B,HuH7)和胆管上皮癌细胞株(SG231,HuCCT1),分别给予不同浓度的外源性PGE2处理,以WST-1细胞增殖实验检测肿瘤细胞增殖率;以RT-PCR实验检测上述细胞4种PGE2受体(EP1、EP2、EP3和EP4)的mRNA表达情况;采用上述肝癌细胞的细胞涂片或细胞爬片进行荧光免疫细胞化学实验,于荧光显微镜和共聚焦显微镜下观察上述4种EP受体蛋白的表达和定位分布。结果:WST-1细胞增殖实验结果显示PGE2可以促进Hep3B和HuH7细胞的生长,但对胆管上皮癌细胞(SG231、HuCCT1细胞)则表现为生长抑制作用;RT-PCR和荧光免疫细胞化学实验结果表明Hep3B、HuH7、SG231和HuCCT1细胞株均有4种EP受体的表达;激光共聚焦结果显示4种EP受体不仅有胞浆、胞膜定位,而且部分在胞核也有表达,其中EP4受体的表达主要定位于细胞核。结论:Hep3B、HuH7、SG231和HuCCT1,4种肝癌细胞株均可以表达EP1、EP2、EP3和EP4受体,且受体的细胞内定位不同。肝癌细胞对前列腺素E2的反应性可能与EP受体的定位以及不同的细胞内信号转导通路激活有关。

Objective： Based on the different reactivity of liver cancer cell lines to PGE2, to investigate the expression and distribution of four kinds of prostaglandin E2 receptors （EP1, EP2, EP3 and EP4） in human hepatoma cells （Hep3B and HUH7） and human cholangiocarcinoma cell lines （SG231 and HuCCT1 ）. Methods： Two human hepatoma cell lines （Hep3B and HUH7） and two human cholangiocarcinoma cell lines （HuCCTI and SG231 ） were cultured and treated with PGE2. The cell growth rate and viability was measured by cell proliferation assay with WST-1 regent. The expression and intracellular localization of EP receptors were determined by RT-PCR and fluorescent immunocytochemistry assay respectively. Results： PGE2 increased the growth of hepatoma cell lines, while inhibited the growth of cholangiocarcinoma cell lines. RT-PCR and fluorescent immunocytochemistry assay showed clearly that all four kinds of EP receptors were detected in human hepatoma cells and cholangiocarcinoma cells. The receptors was not only localized in cytoplasm and membrane but also in nucleolus, especially for EP4 receptor. Conclusion： Hep3B, HUH7, SG231 and HuCCT1 can express all four kinds of PGE2 receptors, but the intracellular location of the receptors is different. The different reactivity of the liver cells may be due to the intracellular location of PGE2 receptors and specific signaling pathway.