Hotair mediates hepatocarcinogenesis through suppressing miRNA-218 expression and activating P14 and P16 signaling

J Hepatol. 2015 Oct;63(4):886-95. doi: 10.1016/j.jhep.2015.05.016. Epub 2015 May 27.


Background & aims: Long non-coding RNA Hotair has been considered as a pro-oncogene in multiple cancers. Although there is emerging evidence that reveals its biological function and the association with clinical prognosis, the precise mechanism remains largely elusive.

Methods: We investigated the function and mechanism of Hotair in hepatocellular carcinoma (HCC) cell models and a xenograft mouse model. The regulatory network between miR-218 and Hotair was elucidated by RNA immunoprecipitation and luciferase reporter assays. Finally, the correlation between Hotair, miR-218 and the target gene Bmi-1 were evaluated in 52 paired HCC specimens.

Results: In this study, we reported that Hotair negatively regulated miR-218 expression in HCC, which might be mediated through an EZH2-targeting-miR-218-2 promoter regulatory axis. Further investigation revealed that Hotair knockdown dramatically inhibited cell viability and induced G1-phase arrest in vitro and suppressed tumorigenicity in vivo by promoting miR-218 expression. Oncogene Bmi-1 was shown to be a functional target of miR-218, and the main downstream targets signaling, P16(Ink4a) and P14(ARF), were activated in Hotair-suppressed tumorigenesis. In primary human HCC specimens, Hotair and Bmi-1 were concordantly upregulated whereas miR-218 was downregulated in these tissues. Furthermore, Hotair was inversely associated with miR-218 expression and positively correlated with Bmi-1 expression in these clinical tissues.

Conclusion: Hotair silence activates P16(Ink4a) and P14(ARF) signaling by enhancing miR-218 expression and suppressing Bmi-1 expression, resulting in the suppression of tumorigenesis in HCC.

Keywords: Hepatocellular carcinoma; Hotair; P14; P16; microR-218.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Carcinogenesis / genetics*
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Survival
  • Cyclin-Dependent Kinase Inhibitor p16
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Immunoprecipitation
  • Liver Neoplasms, Experimental / genetics*
  • Liver Neoplasms, Experimental / metabolism
  • Liver Neoplasms, Experimental / pathology
  • Mice
  • MicroRNAs / biosynthesis
  • MicroRNAs / genetics*
  • Neoplasm Proteins / biosynthesis
  • Neoplasm Proteins / genetics*
  • Promoter Regions, Genetic
  • Proteins / genetics*
  • Proteins / metabolism
  • RNA, Long Noncoding / biosynthesis
  • RNA, Long Noncoding / genetics*
  • RNA, Neoplasm / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / genetics


  • CDKN2A protein, human
  • Cyclin-Dependent Kinase Inhibitor p16
  • HOTAIR long non-coding RNA, mouse
  • LAMTOR2 protein, mouse
  • MIRN218 microRNA, mouse
  • MicroRNAs
  • Neoplasm Proteins
  • Proteins
  • RNA, Long Noncoding
  • RNA, Neoplasm