title: Direct targeting of SUZ12/ROCK2 by miR-200b/c inhibits cholangiocarcinoma tumourigenesis and metastasis.
abstract: BACKGROUND
  The multidrug resistance and distant metastasis of cholangiocarcinoma result in high postoperative recurrence and low long-term survival rates. It has been demonstrated that the ectopic expression of miR-200 suppresses the multidrug resistance and metastasis of cancer. However, the expression and function of miR-200 in cholangiocarcinoma has not yet been described.
  
  
  METHODS
  In this study, we identified dysregulated microRNAs (miRNAs, miR) in cholangiocarcinoma tissue by microarray analysis, and subsequent real-time PCR and northern blot analyses validated the expression of candidate miR. We performed functional analyses and investigated the relationship between miR-200b/c expression and the properties of cholangiocarcinoma cells. A dual luciferase assay was applied to examine the effect of miRNAs on the 3'-UTR of target genes, and we demonstrated the function of the target gene by siRNA transfection identifying the downstream pathway via western blotting.
  
  
  RESULTS
  We found significantly downregulated expression of four miR-200 family members (miR-200a/b/c/429) and then confirmed that ectopic miR-200b/200c inhibits the migration and invasion of cholangiocarcinoma cells both in vitro and in vivo. We found that miR-200b/c influenced the tumourigenesis of cholangiocarcinoma cells including their tumour-initiating capacity, sphere formation, and drug resistance. We further found that miR-200b/c regulated migration and invasion capacities by directly targeting rho-kinase 2 and regulated tumorigenic properties by directly targeting SUZ12 (a subunit of a polycomb repressor complex).
  
  
  CONCLUSIONS
  Our study shows that miR-200b/c has a critical role in the regulation of the tumorigenic and metastatic capacity of cholangiocarcinoma and reveals the probable underlying mechanisms.
authors.affiliation: Department of Biliary-Pancreatic Surgery, Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei 430030, China.
authors.forename: F
authors.initials: F
authors.lastname: Peng
authors.forename: J
authors.initials: J
authors.lastname: Jiang
authors.forename: Y
authors.initials: Y
authors.lastname: Yu
authors.forename: R
authors.initials: R
authors.lastname: Tian
authors.forename: X
authors.initials: X
authors.lastname: Guo
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Shen
authors.forename: M
authors.initials: M
authors.lastname: Xu
authors.forename: F
authors.initials: F
authors.lastname: Zhu
authors.forename: C
authors.initials: C
authors.lastname: Shi
authors.forename: J
authors.initials: J
authors.lastname: Hu
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: R
authors.initials: R
authors.lastname: Qin
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D001650:Bile Duct Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D001653:Bile Ducts, Intrahepatic / Q000473:pathology*; D063646:Carcinogenesis; D045744:Cell Line, Tumor; D018281:Cholangiocarcinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D004195:Disease Models, Animal; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000008:administration & dosage* / Q000235:genetics / Q000378:metabolism; D058990:Molecular Targeted Therapy; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000378:metabolism; D063151:Polycomb Repressive Complex 2 / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors; D014162:Transfection; D023041:Xenograft Model Antitumor Assays; D054460:rho-Associated Kinases / Q000235:genetics* / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; C533896:MIRN200 microRNA, human; D035683:MicroRNAs; D009363:Neoplasm Proteins; C430461:SUZ12 protein, human; D014157:Transcription Factors; D063151:Polycomb Repressive Complex 2; C515852:ROCK2 protein, human; D054460:rho-Associated Kinases