Lv Bei, Ma Lijie, Tang Wenqing, Huang Peixin, Yang Biwei, Wang Lingxiao, Chen She, Gao Qiang, Zhang Si, Xia Jinglin
Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China.
Minhang Hospital, Fudan University, Shanghai, China.
Cell Physiol Biochem. 2018;48(1):158-172. doi: 10.1159/000491715. Epub 2018 Jul 12.
BACKGROUND/AIMS: Intrahepatic cholangiocarcinoma (ICC) is a complicated condition, with difficult diagnosis and poor prognosis. The expression and clinical significance of the farnesoid X receptor (FXR), an endogenous receptor of bile acids, in ICC is not well understood.
Western blotting and immunochemical analyses were used to determine the levels of FXR in 4 cholangiocarcinoma cell lines, a human intrahepatic biliary epithelial cell line (HIBEpic) and 322 ICC specimens, respectively, while quantitative reverse transcription polymerase chain reaction was used to detect the mRNA levels of FXR in cholangiocarcinoma cell lines. We evaluated the prognostic value of FXR expression and its association with clinical parameters. We determined the biological significance of FXR in ICC cell lines by agonist-mediated activation and lentivirus-mediated silence. IL-6 expression was tested by an enzyme-linked immunosorbent assay and flow cytometry. In vitro, cell proliferation was examined by Cell Counting Kit-8, migration and invasion were examined by wound healing and transwell assays; in vivo, tumor migration and invasion were explored in NOD-SCID mice.
FXR was downregulated in ICC cell lines and clinical ICC specimens. Loss of FXR was markedly correlated with aggressive tumor phenotypes and poor prognosis in patients with ICC. Moreover, FXR expression also had significant prognostic value in carbohydrate antigen 19-9 (CA19-9) negative patients. The expression of FXR was negatively correlated with IL-6 levels in clinical ICC tissues. FXR inhibited the proliferation, migration, invasion and epithelial mesenchymal transition (EMT) of ICC cells via suppression of IL-6 in vitro. Obeticholic acid, an agonist of FXR, inhibited IL-6 production, tumor growth and lung metastasis of ICC in vivo.
FXR could be a promising ICC prognostic biomarker, especially in CA19-9 negative patients with ICC. FXR inhibits the tumor growth and metastasis of ICC via IL-6 suppression.
背景/目的：肝内胆管癌（ICC）病情复杂，诊断困难且预后较差。法尼酯X受体（FXR）作为胆汁酸的内源性受体，其在ICC中的表达及临床意义尚不清楚。
分别采用蛋白质免疫印迹法和免疫组化分析法检测4种胆管癌细胞系、1种人肝内胆管上皮细胞系（HIBEpic）及322例ICC标本中FXR的水平，同时采用定量逆转录聚合酶链反应检测胆管癌细胞系中FXR的mRNA水平。我们评估了FXR表达的预后价值及其与临床参数的相关性。通过激动剂介导的激活和慢病毒介导的沉默来确定FXR在ICC细胞系中的生物学意义。采用酶联免疫吸附测定法和流式细胞术检测白细胞介素-6（IL-6）的表达。体外实验中，采用细胞计数试剂盒-8检测细胞增殖，采用伤口愈合实验和Transwell实验检测细胞迁移和侵袭；体内实验中，在非肥胖糖尿病/重症联合免疫缺陷（NOD-SCID）小鼠中探究肿瘤的迁移和侵袭情况。
FXR在ICC细胞系和临床ICC标本中表达下调。FXR缺失与ICC患者的侵袭性肿瘤表型及不良预后显著相关。此外，FXR表达在糖类抗原19-9（CA19-9）阴性患者中也具有显著的预后价值。临床ICC组织中FXR的表达与IL-6水平呈负相关。体外实验中，FXR通过抑制IL-6抑制ICC细胞的增殖、迁移、侵袭及上皮-间质转化（EMT）。FXR激动剂奥贝胆酸在体内可抑制IL-6产生、肿瘤生长及ICC的肺转移。
FXR可能是一种有前景的ICC预后生物标志物，尤其是在CA19-9阴性的ICC患者中。FXR通过抑制IL-6抑制ICC的肿瘤生长和转移。
