Involvement of histone deacetylation in MORC2-mediated down-regulation of carbonic anhydrase IX

Nucleic Acids Res. 2010 May;38(9):2813-24. doi: 10.1093/nar/gkq006. Epub 2010 Jan 27.


Carbonic anhydrase IX (CAIX) plays an important role in the growth and survival of tumor cells. MORC2 is a member of the MORC protein family. The MORC proteins contain a CW-type zinc finger domain and are predicted to have the function of regulating transcription, but no MORC2 target genes have been identified. Here we performed a DNA microarray hybridization and found CAIX mRNA to be down-regulated 8-fold when MORC2 was overexpressed. This result was further confirmed by northern and western blot analysis. Our results also showed that the protected region 4 (PR4) was important for the repression function of MORC2. Moreover, MORC2 decreased the acetylation level of histone H3 at the CAIX promoter. Meanwhile, trichostatin A (TSA) had an increasing effect on CAIX promoter activity. Among the six HDACs tested, histone deacetylase 4 (HDAC4) had a much more prominent effect on CAIX repression. ChIP and ChIP Re-IP assays showed that MORC2 and HDAC4 were assembled on the same region of the CAIX promoter. Importantly, we further confirmed that both proteins are simultaneously present in the PR4-binding complex. These results may contribute to understanding the molecular mechanisms of CAIX regulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / genetics*
  • Antigens, Neoplasm / metabolism
  • Binding Sites
  • Carbonic Anhydrase IX
  • Carbonic Anhydrases / genetics*
  • Carbonic Anhydrases / metabolism
  • Cell Line
  • Down-Regulation*
  • Gene Knockdown Techniques
  • Histone Deacetylases / metabolism*
  • Humans
  • Promoter Regions, Genetic
  • RNA, Messenger / metabolism
  • Repressor Proteins / metabolism*
  • Transcription Factors / antagonists & inhibitors
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Antigens, Neoplasm
  • MORC2 protein, human
  • RNA, Messenger
  • Repressor Proteins
  • Transcription Factors
  • HDAC4 protein, human
  • Histone Deacetylases
  • CA9 protein, human
  • Carbonic Anhydrase IX
  • Carbonic Anhydrases