The dose-response relationship for dicentric chromosomes and γ-H2AX foci in human peripheral blood lymphocytes: Influence of temperature during exposure and intra- and inter-individual variability of donors

Abstract

Purpose: Hypothermia during in vitro irradiation of human peripheral blood lymphocytes (PBL) affects the level of chromosome aberrations. The molecular mechanisms of this phenomenon are not fully understood. The aim of our study was to examine the effect of hypothermia on the dose-response relationship for dicentric chromosomes and the level of γ-H2AX (phosphorylated histone H2AX) foci. In addition, the inter- and intra-individual variability was assessed in relation to temperature.

Materials and methods: PBL were kept at 0.8, 20 and 37°C and then exposed to gamma-rays (from 0–3 Gy). Dicentric chromosomes were scored in first post-treatment mitoses. γ-H2AX foci were scored 15, 30, 60, 120 min and 24 h post irradiation.

Results: Our results revealed that the frequency of dicentric chromosomes in cells exposed at 37°C to gamma-rays was higher than after exposure at 0.8 and 20°C. No effect of temperature was observed on the number of γ-H2AX foci as well as on the intra- and inter-individual variations of the dicentric yield and the number of γ-H2AX foci.

Conclusions: Temperature at exposure to ionizing radiation has a pronounced effect on the level of cytogenetic damage but not γ-H2AX foci.

Keywords::

• γ-H2AX foci
• dicentric chromosomes
• temperature
• ionizing radiation
• human lymphocytes
• inter- and intra-individual variability