Intrinsic Radiosensitivity and PLD Repair in Osteosarcoma Cell Lines

Abstract

The response to radiation of seven osteosarcoma cell lines was analysed by in vitro colony-forming assay and compared with that of eight human fibroblast strains. The values of D₀, the surviving fraction after 2 Gy (S2Gy), and the mean inactivation dose (D¯) of osteosarcoma cells in log-phase culture were significantly higher than those of fibroblast strains (p < 0·01). PLD (potentially lethal damage) repair of osteosarcoma cells evaluated in the plateau phase of growth showed great variation for enhancement of survival, although all of the values were maximized within 12h after irradiation. In the osteosarcoma, intrinsic radiosensitivity in vitro reflected the clinical response to radiation. However, the capacity for PLD repair might not be a good indicator for predicting the results of radiation therapy.