The PRC1 Polycomb group complex interacts with PLZF/RARA to mediate leukemic transformation

Genes Dev. 2009 May 15;23(10):1195-206. doi: 10.1101/gad.512009.

Abstract

Ectopic repression of retinoic acid (RA) receptor target genes by PML/RARA and PLZF/RARA fusion proteins through aberrant recruitment of nuclear corepressor complexes drives cellular transformation and acute promyelocytic leukemia (APL) development. In the case of PML/RARA, this repression can be reversed through treatment with all-trans RA (ATRA), leading to leukemic remission. However, PLZF/RARA ectopic repression is insensitive to ATRA, resulting in persistence of the leukemic diseased state after treatment, a phenomenon that is still poorly understood. Here we show that, like PML/RARA, PLZF/RARA expression leads to recruitment of the Polycomb-repressive complex 2 (PRC2) Polycomb group (PcG) complex to RA response elements. However, unlike PML/RARA, PLZF/RARA directly interacts with the PcG protein Bmi-1 and forms a stable component of the PRC1 PcG complex, resulting in PLZF/RARA-dependent ectopic recruitment of PRC1 to RA response elements. Upon treatment with ATRA, ectopic recruitment of PRC2 by either PML/RARA or PLZF/RARA is lost, whereas PRC1 recruited by PLZF/RARA remains, resulting in persistent RA-insensitive gene repression. We further show that Bmi-1 is essential for the PLZF/RARA cellular transformation property and implicates a central role for PRC1 in PLZF/RARA-mediated myeloid leukemic development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Cell Transformation, Neoplastic*
  • Chromatin / metabolism
  • Humans
  • Leukemia / physiopathology*
  • Nuclear Proteins / metabolism
  • Oncogene Proteins, Fusion / metabolism*
  • Polycomb Repressive Complex 1
  • Polycomb-Group Proteins
  • Protein Binding / drug effects
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins / metabolism
  • Repressor Proteins / metabolism*
  • Tretinoin / pharmacology
  • U937 Cells

Substances

  • Antineoplastic Agents
  • BMI1 protein, human
  • Chromatin
  • Nuclear Proteins
  • Oncogene Proteins, Fusion
  • PLZF-RARalpha fusion protein, human
  • Polycomb-Group Proteins
  • Proto-Oncogene Proteins
  • Repressor Proteins
  • Tretinoin
  • Polycomb Repressive Complex 1