Aurora-a contributes to radioresistance by increasing NF-kappaB DNA binding

Radiat Res. 2010 Sep;174(3):265-73. doi: 10.1667/RR2017.1.

Abstract

Aurora-A, a serine/threonine kinase that is overexpressed in certain human cancer cell lines, plays an important role in mitotic progression. Aurora-A has also been reported to be involved in the activation of nuclear factor kappa B (NF-kappaB). The purpose of the present study was to identify the role of Aurora-A in the radiation-induced activation pathway of NF-kappaB. Wild-type and Aurora-A knockdown (Aurora-A(KD)) HeLa cells were irradiated with 4 Gy of gamma rays and the EMSA, luciferase reporter gene assay and immunoblot analysis were performed. The siRNA-based gene knockdown and overexpression system was adopted to elucidate the role of Aurora-A in radiation-induced NF-kappaB pathway activation. The clonogenic survival study indicated that Aurora-A(KD) cells and the wild-type cells transfected with Aurora-A siRNA or RelA/p65 siRNA were more radiosensitive than the wild-type cells. In both the wild-type and Aurora-A(KD) cells, radiation caused IkappaB kinase-mediated phosphorylation, degradation of IkappaBalpha and phosphorylation of RelA/p65. The nuclear translocation of RelA/p65 was also similar in the wild-type and Aurora-A(KD) cells. However, RelA/p65-DNA binding was markedly suppressed in Aurora-A(KD) cells compared to that in wild-type cells. It was concluded that Aurora-A enhances the binding of NF-kappaB to DNA, thereby increasing the gene transcription by NF-kappaB and decreasing the radiosensitivity of the cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aurora Kinases
  • Blotting, Western
  • Chromatin Immunoprecipitation
  • DNA / metabolism*
  • DNA Primers
  • Electrophoretic Mobility Shift Assay
  • Gene Knockdown Techniques
  • HeLa Cells
  • Humans
  • Microscopy, Fluorescence
  • NF-kappa B / metabolism*
  • Phosphorylation
  • Polymerase Chain Reaction
  • Protein Binding
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • RNA, Small Interfering
  • Radiation Tolerance*

Substances

  • DNA Primers
  • NF-kappa B
  • RNA, Small Interfering
  • DNA
  • Aurora Kinases
  • Protein Serine-Threonine Kinases