Prediction of clonogenic cell survival curves based on the number of residual DNA double strand breaks measured by γH2AX staining
Prediction of clonogenic cell survival curves based on the number of residual DNA double strand breaks measured by γH2AX staining
Menegakis, A.; Yaromina, A.; Eicheler, W.; Dörfler, A.; Beuthien-Baumann, B.; Thames, H. D.; Baumann, M.; Krause, M.
Purpose:
To assess the potential of using the residual phosphorylation of histone H2AX (γH2AX) after irradiation as a marker of radiosensitivity invitro.
Material and methods:
Confluent cell cultures of FaDu and SKX human squamous cell carcinoma lines were irradiated with graded single doses. Twenty-four hours after irradiation cells were seeded for standard colony forming assay (CFA). In parallel, staining for γH2AX was performed to visualise the residual foci.
Results:
In the CFA, FaDu showed a higher radioresistance than SKX. After analysis of the residual foci data, we constructed predicted survival curves using two different methods. First, the proportion of nuclei with <3 foci was found to correlate closely with the observed surviving fraction (SF) in FaDu, with a slight overestimation of the true SF in SKX. Second, there was a strong linear correlation of the mean number of residual foci and observed −lnSF. Based on regression analysis, we calculated the SF for both cell lines based on the mean number of residual γH2AX foci. This second approach again led to a good correlation of predicted and observed SF values in FaDu and a (slight) overestimation in SKX.
Conclusion:In the two cell lines investigated the mean number of residual foci of γH2AX can be used to predict differences in the radiation dose response relationship invitro.
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International Journal of Radiation Biology 85(2009)11, 1032-1041
DOI: 10.3109/09553000903242149
ISSN: 0955-3002
Cited 65 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-13437