Detection of hyperdiploidy and chromosome breakage in interphase human lymphocytes following exposure to the benzene metabolite hydroquinone using multicolor fluorescence in situ hybridization with DNA probes.
Increased frequencies of structural and numerical chromosomal aberrations have been observed in the lymphocytes of benzene-exposed workers. Similar aberrations occurring in bone-marrow cells may contribute to the increased incidence of leukemia seen in these populations. Fluorescence in situ hybridization with chromosome-specific DNA probes is a relatively new technique which shows promise for the identification of aneuploidy-inducing agents. In these studies, fluorescence in situ hybridization with several chromosome-specific DNA probes was used to investigate the ability of the benzene metabolite hydroquinone to induce hyperdiploidy in interphase human lymphocytes. Using a classical satellite probe specific for human chromosome 9, a significant dose-related increase in the frequency of cells containing 3 or more hybridization regions was observed following the in vitro exposure of lymphocytes to hydroquinone at concentrations from 75 to 150 microM. At the 100-microM concentration of hydroquinone, the frequency of nuclei containing 3 or more hybridization regions was determined using probes for chromosomes 1, 7 and 9. Significantly higher frequencies of affected nuclei were observed using the chromosome 1 and 9 probes when compared to the chromosome 7 probe. To establish whether this difference was due to the nonrandom involvement of these chromosomes in hydroquinone-induced hyperdiploidy or to chromosomal breakage within the chromosomal region targeted by these probes, a multicolor fluorescence in situ hybridization approach was developed using probes to two adjacent regions on chromosome 1. Using this tandem-labeling approach, the frequency of nuclei with multiple hybridization regions and the origin of the regions was determined by scoring slides labeled simultaneously with the chromosome 7 alpha satellite probe and the adjacent alpha and classical satellite probes for chromosome 1. The results of these studies confirmed that hydroquinone exposure resulted in a significant increase in hyperdiploid nuclei, but indicated that the different frequency of nuclei containing 3 or more hybridization regions observed using the chromosome 1 and 7 probes, was due to breakage within the chromosomal region targeted by the chromosome 1 classical satellite probe. These results indicate that hydroquinone may contribute significantly to the numerical and structural aberrations observed in benzene-exposed workers. In addition, the multicolor fluorescence in situ hybridization approach utilized in these studies promises to be a powerful technique for the detection of chromosomal breakage occurring in interphase human cells.
Eastmond
D A
DA
Department of Entomology, University of California, Riverside 92521.
Rupa
D S
DS
Hasegawa
L S
LS
D001554:Benzene / Q000378:metabolism; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D002899:Chromosomes, Human, Pair 9; D015342:DNA Probes; D004171:Diploidy; D006801:Humans; D006873:Hydroquinones / Q000633:toxicity*; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects*; D008297:Male; D009153:Mutagens / Q000633:toxicity*
D015342:DNA Probes; D006873:Hydroquinones; D009153:Mutagens; D001554:Benzene; C031927:hydroquinone