CREB up-regulates long non-coding RNA, HULC expression through interaction with microRNA-372 in liver cancer

Nucleic Acids Res. 2010 Sep;38(16):5366-83. doi: 10.1093/nar/gkq285. Epub 2010 Apr 27.

Abstract

Long non-coding RNA (lncRNA), highly up-regulated in liver cancer (HULC) plays an important role in tumorigenesis. Depletion of HULC resulted in a significant deregulation of several genes involved in liver cancer. Although up-regulation of HULC expression in hepatocellular carcinoma has been reported, the molecular mechanisms remain unknown. In this study, we used in vivo and in vitro approaches to characterize cancer-dependent alterations in the chromatin organization and find a CREB binding site (encompassing from -67 to -53 nt) in the core promoter. Besides, we also provided evidence that PKA pathway may involved in up-regulation of HULC. Furthermore, we demonstrated HULC may act as an endogenous 'sponge', which down-regulates a series of microRNAs (miRNAs) activities, including miR-372. Inhibition of miR-372 leads to reducing translational repression of its target gene, PRKACB, which in turn induces phosphorylation of CREB. Over-expression of miR-372 decreases the association of CREB with the proximal promoter, followed by the dissociation of P300, resulting in a change of the histone 'code', such as in deacetylation and methylation. The study elucidates that fine tuning of HULC expression is part of an auto-regulatory loop in which it's inhibitory to expression and activity of miR-372 allows lncRNA up-regulated expression in liver cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / metabolism
  • Cell Line, Tumor
  • Chromatin / chemistry
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / genetics
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Gene Expression Regulation, Neoplastic*
  • Histones / metabolism
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / metabolism
  • MicroRNAs / metabolism*
  • Promoter Regions, Genetic
  • RNA, Untranslated / biosynthesis
  • RNA, Untranslated / genetics*
  • Transcription Factors / metabolism
  • Transcription Initiation Site
  • Transcription, Genetic
  • Transcriptional Activation
  • Up-Regulation

Substances

  • Chromatin
  • Cyclic AMP Response Element-Binding Protein
  • Histones
  • MicroRNAs
  • RNA, Untranslated
  • Transcription Factors
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits
  • Cyclic AMP-Dependent Protein Kinases
  • PRKACB protein, human