Chromatin modifications induced by PML-RARalpha repress critical targets in leukemogenesis as analyzed by ChIP-Chip

Blood. 2008 Mar 1;111(5):2887-95. doi: 10.1182/blood-2007-03-079921. Epub 2007 Nov 16.

Abstract

The translocation t(15;17) generates the chimeric PML-RARalpha transcription factor that is the initiating event of acute promyelocytic leukemia. A global view of PML-RARalpha transcriptional functions was obtained by genome-wide binding and chromatin modification analyses combined with genome-wide expression data. Chromatin immunoprecipitation (ChIP)-chip experiments identified 372 direct genomic PML-RARalpha targets. A subset of these was confirmed in primary acute promyelocytic leukemia. Direct PML-RARalpha targets include regulators of global transcriptional programs as well as critical regulatory genes for basic cellular functions such as cell-cycle control and apoptosis. PML-RARalpha binding universally led to HDAC1 recruitment, loss of histone H3 acetylation, increased tri-methylation of histone H3 lysine 9, and unexpectedly increased trimethylation of histone H3 lysine 4. The binding of PML-RARalpha to target promoters and the resulting histone modifications resulted in mRNA repression of functionally relevant genes. Taken together, our results reveal that the transcription factor PML-RARalpha regulates key cancer-related genes and pathways by inducing a repressed chromatin formation on its direct genomic target genes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Chromatin / metabolism*
  • Chromatin Immunoprecipitation*
  • Gene Expression Profiling
  • Gene Expression Regulation, Leukemic
  • Genome, Human / genetics
  • Histones / metabolism
  • Humans
  • Leukemia / genetics*
  • Leukemia / pathology*
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • Oncogene Proteins, Fusion / genetics
  • Oncogene Proteins, Fusion / metabolism*
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reproducibility of Results
  • Reverse Transcriptase Polymerase Chain Reaction
  • U937 Cells

Substances

  • Chromatin
  • Histones
  • Neoplasm Proteins
  • Oncogene Proteins, Fusion
  • RNA, Messenger
  • promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein