DETECTION OF 1,2,4-BENZENETRIOL INDUCED ANEUPLOIDY AND MICROTUBULE DISRUPTION BY FLUORESCENCE IN-SITU HYBRIDIZATION AND IMMUNOCYTOCHEMISTRY

Fluorescence in situ hybridization (FISH) is becoming increasingly use d to detect chromosomal changes in cancer cytogenetics. Here, we repor t its use in human HL60 cells to detect aneuploidy induced by the benz ene metabolite, 1,2,4-benzenetriol (BT). Human centromeric probes spec ific for chromosomes 9 and 7 were used. Untreated HL60 cells were 0.72 +/- 0.29% hyperdiploid for chromosome 9. Treatment with 5 mu M BT inc reased this level 3-fold to 2.20 +/- 0.87% and 50 mu M increased it 4- fold to 2.96 +/- 0.74%. Similar results were obtained with the chromos ome 7 probe. The induction of aneuploidy by BT is therefore not chromo some-specific nor is it artifactual. Immunocytochemical staining with anti-tubulin antibodies also showed that BT disrupted microtubule orga nization at these concentrations. Thus, mitotic spindle disruption pro bably plays an important role in BT-induced aneuploidy. Trisomy and no t tetrasomy accounted for the majority of the hyperdiploidy induced by BT in the two C-group chromosomes 7 and 9. Since trisomy of C-group c hromosomes is commonly observed ill leukemia, BT-induced aneuploidy ma y be involved in benzene-induced leukemia.