Abstract
Unrepaired and misrepaired DNA Double-Strand Breaks (DSBs) were shown to be the key events of radiation-induced toxicity (radiosensitivity) and genomic instability (cancer proneness), respectively. We have previously shown that immunofluorescence with γ-H2AX and MRE11 biomarkers may account for unrepaired and misrepaired DSBs for doses higher than 1 Gy. Three radiosensitivity groups had been defined (group I: radioresistance; group II: moderate radiosensitivity and cancer proneness; group III: hyperradiosensitivity). Here, we investigated X-ray doses ranging from 9 mGy to 2 Gy in three cell lines representative of these radiosensitivity groups. We observed a non-linear dose-dependent increase of the severity of DSB, suggesting a correlation with the phenomenon of hyper-radiosensitivity to low dose; a non-linear dose-dependent increase of MRE11 foci, revealing a dosethreshold for the radiation-induced genomic instability. Altogether, these data document the evidence of a threshold in low-dose response and strongly suggest the impact of individual factor.
Original language | English |
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Pages (from-to) | 96-106 |
Number of pages | 11 |
Journal | International Journal of Low Radiation |
Volume | 8 |
Issue number | 2 |
DOIs | |
Publication status | Published - Dec 2011 |
Externally published | Yes |
Keywords
- DSB repair
- MRE11
- γ-H2AX