Assessing individual radiosensitivity in human peripheral blood lymphocytes by the method for analysing chromosome aberrations induced by DNA damage in G2 phase

Abstract

Radiotherapy not only kills the cancer cells but also
non-selectively affects the surrounding normal cells. The
method for analysing chromosome aberrations induced
by DNA damage in G2 phase of the cell cycle is expected
to be used to assess the radiosensitivity for improving
treatment efficacy and radiation safety. In this study,
the human peripheral blood lymphocytes samples
were cultured in vitro and irradiated by X-ray sources
with the doses of 0.5; 1.0; 2.0; 4.0 Gy after 69 hours’
cultivation, when most of the lymphocyte cells were in
G2 phase. The samples were continued to be treated
with 4 mM caffeine, cells harvesting and scoring of
microscope slides for determining the chromatid break
frequency in the samples with and without caffeine
treatment. The radiosensitivity was evaluated by IRS =
(G2/G2caffeine) × 100%. The results exhibited that this
method has greatly potential application in assessing
individual radiosensitivity, especially for cancer patients
before radiation therapy.