SIMULTANEOUS EVALUATION OF RADIATION-INDUCED APOPTOSIS AND MICRONUCLEI IN 5 CELL-LINES

Purpose: This study was conducted to clarify the relationship among th e frequencies of micronuclei (MN) and apoptosis, and clonogenic cell s urvival after irradiation. Materials and methods: The frequencies of M N and apoptosis were compared in the surviving fraction in three human tumour cell lines and two rodent cell lines at various irradiation do ses. Results: The SHIN-3, DU-145 and CHO-K1 cells showed dose-dependen t increases of hyper binucleate cell and an excellent correlation betw een the MN frequency and surviving fraction after irradiation. The F9 and COLO 320DM cells did not show this correlation. The number of apop totic cells increased according to the increase in radiation dose in t he F9 and COLO 320DM cells, but not in the SHIN-3, DU-145 or CHO-K1 ce lls. Conclusion: The detection of the MN frequency alone is insufficie nt to measure cellular intrinsic radiosensitivity. The simultaneous us e of the MN assay and the detection of apoptotic cells would be more r eliable as a method for predicting cell survival after radiation.