Induction of minisatellite DNA reanrangements by genotoxic carcinogens in mouse liver tumors

We investigated whether somatic rearrangements in minisatellite DNA are more frequent hi chemically induced mouse liver tumors than they are hi spontane-ous tumors, CD-I mouse liver tumors were induced by either a single dose or 15 consecutive daily doses of 7,12-dimethylbenz[a]anthracene, 4-amlnoazobenzene, N-hydroxy-2-acetyl-aminofluorene or diethylnitrosoamine (DEN). Using DNA fingerprinting analysis, we found that the single- and multiple-dose carcinogen treatments caused a 2- to 5-fold higher frequency of minisatellite DNA rearrangements compared with that found hi spontaneous tumors—with the exception of single-dose DEN tumors, which showed no increase hi rearrangements. O.ir results suggest that DNA fingerprinting may be a valuable assay for differentiating certain chemically induced tumors from spontaneous tumors