Hyperthermia-induced genotoxic effects in human A549 cells

•Hyperthermia induced genotoxic effects in A549 cells.•DNA strand breaks and micronuclei were induced in a temperature- and time-related manner.•DNA strand breaks persisted during post-incubation at 37 °C.•Cytotoxic effects occurred in parallel to the genotoxic effects.•Apoptosis was not significantly induced.

Genotoxic effects of hyperthermia in vitro and in vivo have repeatedly been reported. Short-duration heat shocks and elevated temperature over longer time periods have been shown to induce DNA damage, chromosomal damage and to inhibit DNA repair. Using the comet assay and the micronucleus test, we now investigated temperature- and time-related effects on DNA damage and chromosomal effects of hyperthermia on the A549 human lung cell line. We also related the genotoxic effects to cytotoxic effects and the induction of apoptosis. Our results indicate that exposure to hyperthermia (42–48 °C for 30–120 min) induced genotoxic effects in a temperature- and time-related manner. Interestingly, hyperthermia-induced DNA damage measured by the comet assay was not rapidly removed by post-incubation at 37 °C but even increased after exposure to 48 °C for 60 min. Cytotoxic effects occurred in parallel to the genotoxic effects but apoptosis was not significantly induced under these experimental conditions.