DNA damage by tobacco smoke and some antiblastic drugs evaluated using theComet assay

The Comet assay was used in human leukocytes to detect, in vivo, DNA strand -breaks induced by smoking habit to evaluate the test sensitivity to an env ironmental factor, and by several antiblastic drugs to note their effective ness at single cell level. Differences related to smoking habit, gender and age are evident. Melphalan shows the widest DNA damage. The damage induced by etoposide can be ascribed to the balancing between the production of st rand-breaks and cross-links which limit the migration of DNA fragments. Int erferon, fludarabine, prednisone, and oncocarbide appear to induce unexpect ed strand-breaks. Single cell gel electrophoresis (SCGE) is highly effectiv e in revealing the association between DNA damage and environmental, geneti c, and acquired factors, providing further data on the possible applicabili ty of this assay in genotoxic human surveillance in addition to established tests. Moreover, the ability to point out cell subpopulations varying in m ean damage levels could allow detection of potentially emerging drug-resist ant populations. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved .