Action of Radiation on Synthesis of Deoxyribonucleic Acid in Normal and Tumour Strain Cells

Abstract

Recent data on the effects of radiation on the synthesis of desoxyribonucleic acid (DNA) in normal and tumor-strain cells are reviewed. Results are presented from studies in three types of freshly prepared normal cells grown in culture and in cells from two mouse tumor strains that indicate a time-disconnection of nuclear protein and DNA synthesis in tumor cells. lt is suggested that the differenee in timing of the onset of nuclear protein synthesis reflects a fundamental difference in metabolism between normal and tumor-strain cells. It is concluded that the time-disconnection of DNA and nuclear protein synthesis found in tumor strains implies dislocation of control of phosphorylation. This would be consistent with the lack of radiosensitivity found in the DNA pre-synthetic period in these cells. (C.H.)