Gamma irradiation induces DNA double-strand breaks in fibroblasts: a model study for the development of biodosimetry

International Nuclear Science and Technology Conference 2014

Uttayarat, P.^1 ; Tangtong, T.^1 ; Sukapirom, K.^2 ; Boonsirichai, K.^1

Thailand Institute of Nuclear Technology (Public Organization), Ongkharak, Nakhon Nayok

26120, Thailand^1

Division of Instruments for Research, Faculty of Medicine, Siriraj Hospital, Bangkok

10700, Thailand^2

关键词: Cell culture models;    DNA double strand breaks;    Dose-response curves;    Double strand breaks;    Human dermal fibroblasts;    Phosphorylated histone;    Therapeutic exposure;    Two Dimensional (2 D);   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/611/1/012030/pdf
DOI  :  10.1088/1742-6596/611/1/012030

来源: IOP

【 摘 要 】

Double-strand breaks (DSBs) of DNAs induced by ionizing radiation can pose detrimental damages on organisms which include genetic instability and cell death. It is necessary to be able to assess health risks associated with irradiation from both accidental and therapeutic exposures in a timely manner for proper medical treatments. This present study showed the first attempt to develop a biodosimetric measure in Thailand based on the quantification of phosphorylated histone H2AX (γ-H2AX) formed at DSB sites with an aim to establish a dose response curve using a two-dimensional (2D) cell culture model. Human dermal fibroblasts were grown into monolayers before irradiated by gamma rays from a Co-60 source in a custom-made lead chamber at doses 0, 0.2, 1, 2 and 4 Gy and a dose rate of 0.21 Gy/min. After 30 min post exposure, γ-H2AX proteins were immunofluorescently labelled for evaluation by confocal microscopy and flow cytometry. The accumulation of phosphorylated γ-H2AX proteins at DSBs appeared as nuclear foci with the most prominent intensity at 4 Gy. Linear regression analysis of flow cytometric data showed a linear response (R2= 0.9862) of foci intensity in proportion to irradiation dose. In addition, the fraction of cell viability was shown to decrease at higher doses. This technique can be further developed as a quick assessment tool to identify individuals subjected to accidental radiation in parallel to other established biodosimetric measures.