Changes in the Number of Residual [gamma]H2AX Foci in [Ki-67.sup.-]Positive and [Ki-67.sup.-]Negative Human Fibroblasts Irradiated with X-Rays in Doses of 2-10 Gy

• Published in: Bulletin of experimental biology and medicine Vol. 175; no. 4; p. 450
• Main Authors: Vorobyeva, N.Yu, Osipov, A.A, Chigasova, A.K, Yashkina, E.I, Osipov, A.N
• Format: Journal Article
• Language: English
• Published: Springer 01.08.2023
• Subjects: X-rays
• ISSN: 0007-4888; 1573-8221
• DOI: 10.1007/s10517-023-05883-2

We studied changes in the number of residual [gamma]H2AX foci in cultured human fibroblasts with different expression of the cell proliferation marker protein Ki-67 24, 48, and 72 h after exposure to X-ray radiation in doses of 2-10 Gy. It was shown that, regardless of the expression of Ki-67, the number of residual [gamma]H2AX foci in irradiated cells linearly depends on the absorbed dose of X-ray radiation. However, the quantitative yield of residual [gamma]H2AX foci per unit of the absorbed dose in [Ki-67.sup.+] cells 24 and 48 h after irradiation was higher than in [Ki-67.sup.-] cells by 1.8 and 2.0 times, respectively. In [Ki-67.sup.-] cells, the quantitative yield of residual [gamma]H2AX foci per unit of absorbed dose decreases by ~1.7 times with increasing the time after irradiation from 24 to 72 h. For the purposes of practical radiation biodosimetry, it can be recommended to quantify residual [gamma]H2AX foci in non-proliferating cells at least 72 h after irradiation. Key Words: X-ray radiation; DNA double-strand breaks; residual [gamma]H2AX foci; cell proliferation; human fibroblasts