Impaired repair of ionizing radiation-induced DNA damage in Cockayne syndrome cells
| Autor: | Albert A. van Zeeland, Patricia Cramers, Susy J Santos, Esther E. Verhoeven, Leon H.F. Mullenders, A. Ronald Filon, Jos C. S. Kleinjans, Davy A. P. Rockx, Anneke A. van der Leer |
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| Přispěvatelé: | Toxicogenomics, RS: GROW - School for Oncology and Reproduction |
| Rok vydání: | 2011 |
| Předmět: |
Radiation
DNA Repair DNA damage Cell Survival T-cell receptor Biophysics Dose-Response Relationship Radiation Biology medicine.disease Radiation Dosage Molecular biology Cockayne syndrome Ionizing radiation chemistry.chemical_compound chemistry Transcription (biology) RNA polymerase medicine Humans Radiology Nuclear Medicine and imaging Cockayne Syndrome Gene DNA Cells Cultured DNA Damage |
| Zdroj: | Radiation Research, 175(4), 432-443. Radiation Research Society Radiation Research, 175(4), 432-443 Radiation Research |
| ISSN: | 1938-5404 0033-7587 |
| Popis: | Cramers, P., Verhoeven, E. E., Filon, A. R., Rockx, D. A. P., Santos, S. J., van der Leer, A. A., Kleinjans, J. C. S., van Zeeland, A. A. and Mullenders, L. H. F. Impaired Repair of Ionizing Radiation-Induced DNA Damage in Cockayne Syndrome Cells. Radiat. Res. 175, 432-443 (2011). Cockayne syndrome (CS) cells are defective in transcription-coupled repair (TCR) and sensitive to oxidizing agents, including ionizing radiation. We examined the hypothesis that TCR plays a role in ionizing radiation-induced oxidative DNA damage repair or alternatively that CS plays a role in transcription elongation after irradiation. Irradiation with doses up to 100 Gy did not inhibit RNA polymerase II-dependent transcription in normal and CS-B fibroblasts. In contrast, RNA polymerase I-dependent transcription was severely inhibited at 5 Gy in normal cells, indicating different mechanisms of transcription response to X rays. The frequency of radiation-induced base damage was 2 x 10(-7) lesions/base/Gy, implying that 150 Gy is required to induce one lesion/30-kb transcription unit; no TCR of X-ray-induced base damage in the p53 gene was observed. Therefore, it is highly unlikely that defective TCR underlies the sensitivity of CS to ionizing radiation. Overall genome repair levels of radiation-induced DNA damage measured by repair replication were significantly reduced in CS-A and CS-B cells. Taken together, the results do not provide evidence for a key role of TCR in repair of radiation-induced oxidative damages in human cells; rather, impaired repair of oxidative lesions throughout the genome may contribute to the CS phenotype. |
| Databáze: | OpenAIRE |
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