Effects of an inhibitor of topoisomerase II, ICRF-193 on the formation of ultraviolet-induced chromosomal aberrations.
Treatments of Chinese hamster V79 cells during one cell cycle with a new type of topoisomerase II inhibitor, ICRF-193, which does not accumulate cleavable topoisomerase-DNA complexes induced both chromosome- and chromatid-type aberrations with high frequencies. Furthermore, ICRF-193 synergistically enhanced the yield of UVB-induced chromatid-type aberrations, chromatid exchanges in particular. Treated with ICRF-193 for the last 3 h before harvest, cells showed frequent incidence of chromatid-type aberrations and synergistic enhancement of UVB-induced chromatid-type aberrations, chromatid exchanges in particular. These results suggest that spontaneous and UVB-induced lesions might be ultimately transformed into chromatid-type aberrations by topoisomerase II-dependent checkpoint process(es) in the G2 phase of the cell cycle.
Ikushima
T
T
Biology Division, Kyoto University of Education, 1 Fukakusa-Fujinomori-cho, Fushimi-ku, Kyoto 612-0863, Japan. ikushima@wsml.kyokyo-u.ac.jp
Shima
Y
Y
Ishii
Y
Y
D000818:Animals; D002478:Cells, Cultured; D002842:Chromatids / Q000528:radiation effects; D002869:Chromosome Aberrations / Q000235:genetics*; D002875:Chromosomes / Q000528:radiation effects*; D006224:Cricetinae; D003412:Cricetulus; D004260:DNA Repair / Q000235:genetics; D054659:Diketopiperazines; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007399:Interphase / Q000235:genetics; D010879:Piperazines / Q000494:pharmacology*; D059005:Topoisomerase II Inhibitors; D014466:Ultraviolet Rays
D054659:Diketopiperazines; D004791:Enzyme Inhibitors; D010879:Piperazines; D059005:Topoisomerase II Inhibitors; C070899:4,4'-(1,2-dimethyl-1,2-ethanediyl)bis-2,6-piperazinedione