Induction and Rejoining of DNA Double Strand Breaks Assessed by H2AX Phosphorylation in Melanoma Cells Irradiated with Proton and Lithium Beams

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2009.02.070· OSTI ID:21281978

Ibanez, Irene L ^[1]; Bracalente, Candelaria ^[1]; Molinari, Beatriz L ^[1]; Palmieri, Monica A ^[2]; Policastro, Lucia ^[1]; Kreiner, Andres J ^[1]; Burlon, Alejandro A ^[1]; Valda, Alejandro ^[3]; Navalesi, Daniela ^[2]; Davidson, Jorge; Davidson, Miguel ^[4]; Vazquez, Monica; Ozafran, Mabel ^[1]; Duran, Hebe ^[1]

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1. Comision Nacional de Energia Atomica, San Martin (Argentina)
2. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)
3. Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin (Argentina)
4. Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina)

Purpose: The aim of this study was to evaluate the induction and rejoining of DNA double strand breaks (DSBs) in melanoma cells exposed to low and high linear energy transfer (LET) radiation. Methods and Materials: DSBs and survival were determined as a function of dose in melanoma cells (B16-F0) irradiated with monoenergetic proton and lithium beams and with a gamma source. Survival curves were obtained by clonogenic assay and fitted to the linear-quadratic model. DSBs were evaluated by the detection of phosphorylated histone H2AX ({gamma}H2AX) foci at 30 min and 6 h post-irradiation. Results: Survival curves showed the increasing effectiveness of radiation as a function of LET. {gamma}H2AX labeling showed an increase in the number of foci vs. dose for all the radiations evaluated. A decrease in the number of foci was found at 6 h post-irradiation for low LET radiation, revealing the repair capacity of DSBs. An increase in the size of {gamma}H2AX foci in cells irradiated with lithium beams was found, as compared with gamma and proton irradiations, which could be attributed to the clusters of DSBs induced by high LET radiation. Foci size increased at 6 h post-irradiation for lithium and proton irradiations in relation with persistent DSBs, showing a correlation with surviving fraction. Conclusions: Our results showed the response of B16-F0 cells to charged particle beams evaluated by the detection of {gamma}H2AX foci. We conclude that {gamma}H2AX foci size is an accurate parameter to correlate the rejoining of DSBs induced by different LET radiations and radiosensitivity.

• OSTI ID: 21281978
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 74; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BEAMS
DNA
GAMMA SOURCES
IONIZING RADIATIONS
IRRADIATION
LET
LITHIUM
MELANOMAS
PHOSPHORYLATION
PROTONS
RADIATION DOSES
RADIOSENSITIVITY
STRAND BREAKS
SURVIVAL CURVES