Direct targeting of SUZ12/ROCK2 by miR-200b/c inhibits cholangiocarcinoma tumourigenesis and metastasis

Br J Cancer. 2013 Dec 10;109(12):3092-104. doi: 10.1038/bjc.2013.655. Epub 2013 Oct 29.

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).

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Bile Duct Neoplasms / genetics*
  • Bile Duct Neoplasms / metabolism
  • Bile Duct Neoplasms / pathology
  • Bile Duct Neoplasms / therapy*
  • Bile Ducts, Intrahepatic / pathology*
  • Carcinogenesis
  • Cell Line, Tumor
  • Cholangiocarcinoma / genetics*
  • Cholangiocarcinoma / metabolism
  • Cholangiocarcinoma / pathology
  • Cholangiocarcinoma / therapy*
  • Disease Models, Animal
  • Drug Resistance, Neoplasm
  • Female
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • MicroRNAs / administration & dosage*
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Molecular Targeted Therapy
  • Neoplasm Metastasis
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / metabolism
  • Polycomb Repressive Complex 2 / genetics*
  • Polycomb Repressive Complex 2 / metabolism
  • Transfection
  • Xenograft Model Antitumor Assays
  • rho-Associated Kinases / genetics*
  • rho-Associated Kinases / metabolism

Substances

  • 3' Untranslated Regions
  • MIRN200 microRNA, human
  • MicroRNAs
  • SUZ12 protein, human
  • Polycomb Repressive Complex 2
  • ROCK2 protein, human
  • rho-Associated Kinases