Study on γH2AX Expression of Lymphocytes as a Biomarker In Radiation Biodosimetry

Flow cytometry analysis was used to detect the changes of γH2AX protein expression in human peripheral blood lymphocytes. In the dose-effect study, the expression of γH2AX was detected 1 h after irradiation with 60Co γ-rays at doses of 0, 0.5, 1, 2, 4, and 6 Gy. Blood was cultivated for 0, 1, 2, 4, 6, 12, and 24 h after 4 Gy ⁶⁰Co γ-rays irradiation for the time-effect study. At the same time, the blood was divided into four treatment groups (ultraviolet [UV] irradiation, ⁶⁰Co γ-rays irradiation, UV plus ⁶⁰Co γ-rays irradiation, and control group) to detect the changes of protein expression of γH2AX. The results showed that the γH2AX protein expression was in dose-effect and time-effect relationship with ⁶⁰Co γ-rays. The peak expression of γH2AX was at 1 h after ⁶⁰Co γ-ray irradiation and began to decrease quickly. Compared to irradiation with ⁶⁰Co γ-rays alone, the expression of γH2AX was not significantly changed after irradiation with ⁶⁰Co γ-rays plus UV. Dose rate did not significantly change the expression of γH2AX. The expression of γH2AX induced by ⁶⁰Co γ-rays was basically consistent with the mice in vivo and in vitro. The results revealed that the detection of γH2AX protein expression changes in peripheral blood lymphocyte by flow cytometry analysis is reasonable and may be useful for biodosimetry.