Expression of genes involved in repair of DNA double-strand breaks in normal and tumor tissues

Koh Ichi Sakata, Yoshihisa Matsumoto, Hiroshi Tauchi, Masaaki Satoh, Atushi Oouchi, Hisayasu Nagakura, Kazumitsu Koito, Yoshio Hosoi, Norio Suzuki, Kenshi Komatsu, Masato Hareyama

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)


Background: DNA double-strand breaks (DSB) are the major lethal lesions induced by ionizing radiation. The capability for DNA DSB repair is crucial for inherent radiosensitivity of tumor and normal cells. DNA-PKcs, Ku 70, Ku 85, Xrcc4, and Nbs1 play a critical role in DNA DSB repair. Methods: We immunohistochemically investigated the expression of DNA-PKcs, Ku 70, Ku85, Xrcc4, and Nbs1 in 134 specimens from various normal and tumor tissues with different radiosensitivity. Results and Conclusion: Immunopositivity to Ku70, Ku85, DNA-PKcs, Xrcc4, and Nbs1 was found in all tumor tissues examined. The staining for Ku70, Ku85, and DNA-PKcs was nuclear; but, for Xrcc4 and Nbs1, it was nuclear and cytoplasmic. There were no apparent differences in the expression of these five proteins among cancerous tissues and the corresponding normal tissues. No apparent differences in nuclear staining intensity were detected in the expression of these five proteins among tumor tissues with different radiosensitivity, although non-Hodgkins' lymphoma (B or T cell) tended to show a lower expression than the others. The stromal cells generally expressed these five proteins at much lower frequency than either tumor or epithelial cells in both tumor and normal tissues.

Original languageEnglish
Pages (from-to)161-167
Number of pages7
JournalInternational Journal of Radiation Oncology Biology Physics
Issue number1
Publication statusPublished - 2001 Jan 1
Externally publishedYes


  • Cancer
  • DNA double-strand breaks
  • DNA repair
  • Immunohistochemistry
  • Radiosensitivity

ASJC Scopus subject areas

  • Radiation
  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research


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