An explanation for the S-phase specificity of the cytotoxicity of protein synthesis inhibitors

Abstract

A pulse of the protein synthesis inhibitor cycloheximide is shown to induce chromosome aberrations in cultured cells of human origin. These aberrations do not appear until in excess of 12 hr after the pulse and their appearance coincides with the time when cells which had been in S-phase at the time of the cycloheximide pulse reach mitosis. We suggest that the reason why the protein synthesis inhibitor cycloheximide has previously been reported not to induce chromosome aberrations is due to the long delay of cells with damaged chromosomes in reaching mitosis.