Misrepair of DNA double-strand breaks in patient with unidentified chromosomal fragility syndrome and family history of radiosensitivity

Ghazi Alsbeih, Williams Brock, Michael Story

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Purpose: To test the hypothesis that differences in DNA double-strand breaks (DSB) repair fidelity underlies differences in radiosensitivity. Materials and methods: A primary fibroblast culture (C42) derived from a pediatric cancer patient treated with reduced radiation doses consequent to a family history of radiosensitivity reminiscent of chromosomal fragility syndrome, was compared to a normal control (C29). DNA DSB rejoining and repair fidelity were studied by Southern blotting and hybridization to specific fragments: Alu repetitive sequence representing the overall DSB rejoining capacity in the genome and a 3.2 Mbp NotI restriction fragment on chromosome 21 for DSB repair fidelity. Results: Although both assays showed statistically significant difference (p ≤ 0.05) between the two cell strains in residual misrepaired (un-or mis-rejoined) DSB (24 h after 30 or 80 Gy), the residual damage was lower in the Alu enriched genome assay compared to NotI assay (0.01-0.07 and 0.10-0.37, respectively). Conclusions: These results suggest that, in comparison to classic DSB repair experiment, an assay of measuring DNA DSB repair fidelity can provide better resolution and a more accurate estimate of misrepair of radiation-induced DNA damage, which underlies genomic instability and increased radiosensitivity.

Original languageEnglish (US)
Pages (from-to)53-59
Number of pages7
JournalInternational Journal of Radiation Biology
Volume90
Issue number1
DOIs
StatePublished - Jan 2014

Keywords

  • DNA double-strand breaks
  • Human fibroblasts
  • Misrepair
  • NotI fragment
  • PFGE
  • Radiosensitivity

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging

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