Induction and quantification of gamma-H2AX foci following low and high LET-irradiation.

Journal article

PURPOSE: To investigate quantitatively the induction and rejoining of DNA double strand breaks (DSB) in V79-4 and xrs-5 Chinese hamster cells and HF19 human fibroblast cells, using the phosphorylation of the histone protein H2AX (gamma-H2AX) as an indicator of DSB, exposed to low doses of either low linear energy transfer (LET) (60)Co gamma-rays or high LET a-particles. MATERIALS AND METHODS: Cells were irradiated with low or high LET (20 - 2000 mGy). The gamma-H2AX foci were detected using immunohistochemistry and quantified by image analysis. RESULTS: The number of DSB determined 30 min post gamma-irradiation at 37 degrees C is 12.2 (+/-1.5), 13.5 (+/-1.6) and 19.1 (+/-1.7) foci/cell/Gy for V79-4, xrs-5 and HF19 cells respectively, comparable with levels detected in V79-4 cells using pulse field gel electrophoresis. 6 h post gamma-irradiation, gamma-H2AX foci levels in V79-4 and HF19 cells approach control levels but remain higher in DSB repair deficient xrs-5 cells. Gamma-H2AX foci levels remain significantly higher than controls at 6 h in a-irradiated cells. CONCLUSIONS: Gamma-radiation and alpha-radiation induced the phosphorylation of H2AX in response to DSB at low doses; the variation in the rate of dephosphorylation of induced foci are dependent both on radiation quality and cell characteristics.

Authors: Leatherbarrow, E; Harper, J; Cucinotta, F; O'Neill, P

• Publication status: Published
• Journal: International journal of radiation biology
• Volume: 82
• Issue: 2
• Pages: 111-118
• Publication date: 2006-02-01
• DOI: 10.1080/09553000600599783
• EISSN: 1362-3095
• ISSN: 0955-3002
• Language: English
• Keywords: Cricetinae; Animals; Fibroblasts; Dose-Response Relationship, Radiation; Alpha Particles; Humans; Radiation Dosage; Gamma Rays; DNA; Histones; Cell Line; DNA Damage; Linear Energy Transfer; Cricetulus