Transcriptional response to ionizing radiation in human radiation sensitive cell lines

Background and purpose: Radiation is a common treatment of cancer, but some patients show severe side effects when exposed to small doses of radiation. The aim of this study was to explore the underlying cause of radiation sensitivity in a group of radiation sensitive patients. Materials and methods: Lymphoblastoid cell lines from 5 normal individuals, 4 Ataxia Telangiectasia (AT), and 12 non-AT radiation sensitive (IRS) patients were irradiated. RNA was isolated before and after radiation and hybridized to 15k cDNA microarrays and gene expression was recorded. Results and conclusion: The IRS cell lines showed an expression phenotype different from both the AT and normal cell lines. Six of the IRS cell lines had a distinct expression profile before radiation. This implies that the IRS patients are a heterogeneous group, but that six of the patients may have a common cause of radiation sensitivity. (C) 2007 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 83 (2007) 256-260.