Radiation-dependent apoptosis on cultured thyroid cells.

: Aim of this investigation is the study of the modifications and the DNA damage occurring in thyroid cells exposed to radiation. The FRTL-5 rat thyroid cell strain has been chosen for this study. Objects of this research are both Ionizing radiation, of fundamental interest for space missions, and the UV radiation, (also mutagen and frequent cause of several cancer forms). The present study of UV radiation represents a preliminarily tool to investigate the biological radiation damage. FRTL-5 cells have been irradiated with doses of UV-C (254 nm wavelength) ranging from 15 to 80 Joule/m2. The DNA damage has been analyzed with the 'DNA ladder by gel electrophoresis' technique. DNA has been extracted at 24 and 48 hours from irradiation. At 24h the apoptotic process is not detectable. At 48 h from irradiation, cells show the characteristic signs of apoptosis. The lower dose to which the apoptotic process is detectable, corresponds to 20 Joule/m2. At the higher doses a bigger percentage of cells undergoes apoptosis. These data confirms that the FRTL-5 biological system is particularly suitable for further studies on the biological mechanisms of radiation damage.