Aurora A is a repressed effector target of the chromatin remodeling protein INI1/hSNF5 required for rhabdoid tumor cell survival

Cancer Res. 2011 May 1;71(9):3225-35. doi: 10.1158/0008-5472.CAN-10-2167. Epub 2011 Apr 26.

Abstract

Rhabdoid tumors (RT) are aggressive pediatric malignancies with poor prognosis. INI1/hSNF5 is a component of the chromatin remodeling SWI/SNF complex and a tumor suppressor deleted in RT. Previous microarray studies indicated that reintroduction of INI1/hSNF5 into RT cells leads to repression of a high degree of mitotic genes including Aurora Kinase A (Aurora A, STK6). Here, we found that INI1/SNF5 represses Aurora A transcription in a cell-type-specific manner. INI1-mediated repression was observed in RT and normal cells but not in non-RT cell lines. Chromatin immunoprecipitation (ChIP) assay indicated that INI1/hSNF5 associates with Aurora A promoter in RT and normal cells but not in non-RT cells. Real-time PCR and immunohistochemical analyses of primary human and mouse RTs harboring mutations in INI1/hSNF5 gene indicated that Aurora A was overexpressed/derepressed in these tumor cells, confirming that INI1/hSNF5 represses Aurora A in vivo. Knockdown of Aurora A impaired cell growth, induced mitotic arrest and aberrant nuclear division leading to decreased survival, and increased cell death and caspase 3/7-mediated apoptosis in RT cells (but not in normal cells). These results indicated that Aurora A is a direct downstream target of INI1/hSNF5-mediated repression in RT cells and that loss of INI1/hSNF5 leads to aberrant overexpression of Aurora A in these tumors, which is required for their survival. We propose that a high degree of Aurora A expression may play a role in aggressive behavior of RTs and that targeting expression or activity of this gene is a novel therapeutic strategy for these tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Aurora Kinase A
  • Aurora Kinases
  • Caspase 3 / metabolism
  • Caspase 7 / metabolism
  • Cell Growth Processes
  • Cell Line, Tumor
  • Chromatin Assembly and Disassembly
  • Chromosomal Proteins, Non-Histone / biosynthesis
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Knockdown Techniques
  • HeLa Cells
  • Humans
  • Jurkat Cells
  • Mice
  • Mitosis / physiology
  • Molecular Targeted Therapy
  • Promoter Regions, Genetic
  • Protein Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein Serine-Threonine Kinases / biosynthesis
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • RNA, Small Interfering / administration & dosage
  • RNA, Small Interfering / genetics
  • Rhabdoid Tumor / enzymology*
  • Rhabdoid Tumor / genetics
  • Rhabdoid Tumor / pathology
  • SMARCB1 Protein
  • Transcription Factors / biosynthesis
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transfection
  • Transplantation, Heterologous

Substances

  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • RNA, Small Interfering
  • SMARCB1 Protein
  • SMARCB1 protein, human
  • Transcription Factors
  • AURKA protein, human
  • Aurka protein, mouse
  • Aurora Kinase A
  • Aurora Kinases
  • Protein Serine-Threonine Kinases
  • Caspase 3
  • Caspase 7