Induction of Sister Chromatid Exchanges in Chinese Hamster Cells by Antitumor Agents and Its Relation to Chromosome Aberrations

Abstract

Various antitumor agents were used to investigate the induction of sister chromatid exchanges (SCEs), one of the most sensitive tests for detecting the effects of mutagenic carcinogens. Antimetabolites in nucleic acid synthesis and inhibitors of protein synthesis were tested on Chinese hamster cells in vitro. These agents increased the frequency of SCEs even after a one hour exposure, and during the limited stage of the last cell division cycle beforefixation. In chase experiments, the response curves of SCEs and chromosomeaberrations were somewhat similar, but seemed to fluctuate independent of each other. Chromosome breaks and gaps induced by the agents were not necessarily associated with SCEs at the breakpoints. Possible relationships between SCE formation and chromosome aberrations are discussed.