title: PTEN and PDCD4 are bona fide targets of microRNA-21 in human cholangiocarcinoma.
abstract: OBJECTIVE
  To investigate the expression profile of microRNA-21 in human cholangiocarcinoma tissues and to validate its bona fide targets in human cholangiocarcinoma cells.
  
  
  METHODS
  The expression profile of microRNA-21 in human cholangiocarcinoma tissues and cholangiocarcinoma cell line, QBC939, was evaluated by using real-time PCR analysis. The bona fide targets of microRNA-21 were analyzed and confirmed by dual luciferase reporter gene assay and western blot, respectively. The expressional correlation of microRNA-21 and its targets was probed in human cholangiocarcinoma tissues by using real-time PCR, locked nucleic acid in situ hybridization (LNA-ISH), and immunohistochemistry analysis.
  
  
  RESULTS
  Real-time PCR analysis revealed that microRNA-21 expression depicted a significant up-regulation in human cholangiocarcinoma tissues about 5.6-fold as compared to the matched normal bile duct tissues (P<0.05). The dual luciferase reporter gene assay revealed endogenous microRNA-21 in cholangiocarcinoma cell line, QBC939, inhibited the luciferase reporter activities of wild-type PTEN (P<0.01) and PDCD4 (P<0.05) and had no this effect on mutated PTEN and PDCD4. Moreover, loss of microRNA-21 function led to a significant increase of PTEN and PDCD4 protein levels in QBC939 cells. Elevated microRNA-21 levels were accompanied by marked reductions of PTEN and PDCD4 expression in the same cholangiocarcinoma tissue.
  
  
  CONCLUSIONS
  microRNA-21 expression is up-regulated in human cholangiocarcinoma and PTEN, PDCD4 are direct effectors of microRNA-21.
authors: Department of Biochemistry, National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, and Department of General Surgery, Peking Union Medical College Hospital, Beijing 100005, China. cz-liu@ibms.pumc.edu.cn
authors: Chang-zheng
authors: CZ
authors: Liu
authors: Wei
authors: W
authors: Liu
authors: Yi
authors: Y
authors: Zheng
authors: Jin-mei
authors: JM
authors: Su
authors: Jing-jing
authors: JJ
authors: Li
authors: Lan
authors: L
authors: Yu
authors: Xiao-dong
authors: XD
authors: He
authors: Song-sen
authors: SS
authors: Chen
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D001650:Bile Duct Neoplasms / Q000235:genetics* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D018281:Cholangiocarcinoma / Q000235:genetics* / Q000473:pathology; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D008875:Middle Aged; D051059:PTEN Phosphohydrolase / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics*; D014162:Transfection
chemical_list: D051017:Apoptosis Regulatory Proteins; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; C114487:PDCD4 protein, human; D016601:RNA-Binding Proteins; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human