Production of sister chromatid exchanges by various cancer chemotherapeutic agents.

Various cancer chemotherapeutic agents have been examined for their ability to produce increases in sister chromatid exchanges. Those agents which had been shown previously to produce oncogenic transformation as well as chromosomal breaks also showed significant increases in sister chromatid exchanges. Those drugs which had not been shown to be oncogenic or clastogenic in cell culture produced no increases in sister chromatid exchanges. In general, concentrations which yielded increases in sister chromatid exchanges were considerably lower than those which had been shown previously to produce oncogenic transformation and chromosomal breakage. This was particularly true for the alkylating agents. Thus, we concur that examining increases in the production of sister chromatid exchanges may be an additional sensitive method for detecting potential mutagenic and/or oncogenic agents in our environment.