title: Raf kinase inhibitor protein inhibits cholangiocarcinoma cell metastasis by downregulating matrix metalloproteinase 9 and upregulating tissue inhibitor of metalloproteinase 4 expression.
abstract: Cholangiocarcinoma cells originate in the biliary epithelium. The cells easily metastasize and cause relapse. The effect of Raf kinase inhibitor protein (RKIP) on the biological behavior of cholangiocarcinoma cells is not yet clear. In the present study, RKIP and cytokeratin 19 expression was detected in the extrahepatic tissues of cholangiocarcinoma patients by immunohistochemistry. RKIP small interfering (si)RNA or an RKIP-overexpressing adenoviral vector were used to infect the human cholangiocarcinoma RBE cell line. RKIP protein or gene expression was analyzed by western blotting or reverse transcription-quantitative polymerase chain reaction (RT-qPCR), respectively. The cells were assayed for proliferation, apoptosis, invasion and migration. Matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinase 4 (TIMP-4) mRNA was assayed by RT-qPCR. RKIP expression was reduced in the extrahepatic cholangiocarcinoma tumor compared with the adjacent uninvolved peritumoral tissues. The current study revealed that RKIP expression was positively correlated with cell differentiation, but negatively correlated with lymph node or distant metastasis (P<0.05). RKIP siRNA treatment promoted RBE cell invasion, but RKIP overexpression prevented cell invasion. In the pDC316-siRNA recombinant vector group, the cells migrated more quickly compared with the siRNA-negative control group, and in the RKIP-expressing adenoviral vector group, the cells migrated more slowly compared with the adenoviral negative control group. RKIP inhibited the invasive and metastatic ability of the cholangiocarcinoma cell line, RBE, by downregulating MMP-9 and upregulating TIMP-4 mRNA expression. RKIP is negatively associated with cholangiocarcinoma distant metastasis and prevents cholangiocarcinoma cell metastasis through downregulating MMP-9 expression and upregulating TIMP-4 expression.
authors.affiliation: Department of Gastroenterology, The Second Hospital of Hebei Medical University, Hebei Key Laboratory of Gastroenterology, Hebei Institute of Gastroenterology, Shijiazhuang, Hebei 050000, P.R. China.
authors.forename: Junji
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Gastroenterology, The Second Hospital of Hebei Medical University, Hebei Key Laboratory of Gastroenterology, Hebei Institute of Gastroenterology, Shijiazhuang, Hebei 050000, P.R. China.
authors.forename: Junli
authors.initials: J
authors.lastname: Shi
authors.affiliation: Department of Gastroenterology, The Second Hospital of Hebei Medical University, Hebei Key Laboratory of Gastroenterology, Hebei Institute of Gastroenterology, Shijiazhuang, Hebei 050000, P.R. China.
authors.forename: Dongqiang
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Department of Gastroenterology, The Second Hospital of Hebei Medical University, Hebei Key Laboratory of Gastroenterology, Hebei Institute of Gastroenterology, Shijiazhuang, Hebei 050000, P.R. China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Hepatobiliary Surgery, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Molecular Biology, Basic Medical College of Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Department of Gastroenterology, The Second Hospital of Hebei Medical University, Hebei Key Laboratory of Gastroenterology, Hebei Institute of Gastroenterology, Shijiazhuang, Hebei 050000, P.R. China.
authors.forename: Huiqing
authors.initials: H
authors.lastname: Jiang
keywords: Raf kinase inhibitor protein; cholangiocarcinoma; invasion; migration