Comparison of response to radiation, hyperthermia and cisplatin in parental and polymerase β knockout cells

Abstract

The role of polymerase g in response to radiation, cisplatin and hyperthermia was examined in a pair of mouse cell lines, comprising a normal parental line and a derivative with polymerase g knockout. Cell survival was assessed using the colony survival assay. For irradiation, there was no difference in response between the two cell lines. Treatment with cisplatin for 1h showed a large increase in resistance in the mutant cell line. The results with hyperthermia were more complex. The mutant was more resistant to 45°C heating, but was slightly more heat sensitive than the wild type at 41°C. Thus, in summary, while the knockout of polymerase g did not alter radiation sensitivity, it did increase resistance to cisplatin and induced resistance to hyperthermia at higher temperatures (45°C).