Problems of Radiation Medicine and Radiobiology

EXPRESSION OF γ-H2AX HISTONE IN LYMPHOCYTES OF THE CHORNOBYL “SHELTER” OBJECT STAFF EXPOSED TO IONIZING RADIATION IN OCCUPATIONAL LIMITS

D. A. Bazyka, K. D. Muzalevska, O. L. Maznichenko, O. A. Belyaev
State Institution “National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine”, Melnykov str., 53, Kyiv, 04050, Ukraine

Objective. To compare the effect of radiation dose and time after exposure on formation of γ-H2AX histone in Chornobyl clean-up workers and personnel who perform work activities at the zone of high radiation risks.
Materials and Methods. The expression of γ-H2AX histone in peripheral blood lymphocytes of 68 patients, including 33 “Shelter” workers after recent radiation exposure in professional limits and comparison group of 35 Chornobyl clean-up workers exposed 24–27 years before, the study by flow cytometry.
Results. An increase of the expression of γ-H2AX histone in lymphocytes was revealed in “Shelter” staff after leaving the area of work (0,70±0,93) (M±SD), comparing with Chornobyl clean-up workers (0,51 ± 0,27) (M ± SD), р < 0,001. Analysis subgroups of clean-up workers divided by doses (100–250 mSv, n = 20 and 250–1000 mSv, n = 16) we found connection between radiation dose and the percentage of γ-H2AX positive cells. The number of γ-H2AX positive cells was higher in a subgroup with higher doses (0,49 ± 0,05 and 0,55 ± 0,08, (M ± SD, respectively, p < 0.01)).
Conclusions. Our study suggests the possibility of determining γ-H2AX histone as a marker of cellular radiosensitivity and possibility to use it as a diagnostic tool of a recent radiation exposure at low doses in humans.

Key words. Ionizing radiation, γ-H2AX histone, radiation, lymphocyte, Chornobyl.

Problems of radiation medicine and radiobiology. 2014;19:186-191.