DNA-PKcs and ATM influence generation of ionizing radiation-induced bystander signals

R. T. Hagelstrom, K. F. Askin, A. J. Williams, L. Ramaiah, C. Desaintes, E. H. Goodwin, R. L. Ullrich, S. M. Bailey

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


The phenomenon by which irradiated cells influence non-irradiated neighboring cells, referred to as the bystander effect (BSE), is not well understood in terms of the underlying pathways involved. We sought to enlighten connections between DNA damage repair and the BSE. Utilizing sister chromatid exchange (SCE) frequencies as a marker of the BSE, we performed cell transfer strategies that enabled us to distinguish between generation versus reception of a bystander signal. We find that DNA-dependent Protein Kinase catalytic subunit (DNA-PKcs) and Ataxia Telangectasia Mutated (ATM) are necessary for the generation of such a bystander signal in normal human cells following gamma (γ)-ray exposure, but are not required for its reception. Importantly, we also show that directly irradiated human cells do not respond to receipt of a bystander signal, helping to explain why the BSE is a low-dose phenomenon. These studies provide the first evidence for a role of the DNA damage response proteins DNA-PKcs and ATM specifically in the generation of a bystander signal and intercellular signaling.

Original languageEnglish (US)
Pages (from-to)6761-6769
Number of pages9
Issue number53
StatePublished - Nov 13 2008
Externally publishedYes


  • ATM
  • Bystander effect
  • DNA-PKcs
  • Ionizing radiation

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cancer Research


Dive into the research topics of 'DNA-PKcs and ATM influence generation of ionizing radiation-induced bystander signals'. Together they form a unique fingerprint.

Cite this