Detection of numerical chromosomal aberrations by flow cytometry: a novel process for identifying aneugenic agents.

Aneuploidy plays a significant role in adverse human health conditions including birth defects, pregnancy wastage, and cancer. Currently, there is no screening method sufficiently validated that can be used routinely to identify aneugenic agents in vitro because most conventional test systems rely on the labor-intensive microscopic assessment of the aneuploid cell population. Our laboratory has recently developed a flow cytometry-based procedure for assessing numerical chromosomal aberrations in mitotic populations of lymphocytes on the basis of DNA content. Studies were conducted in 24 h treated human lymphocyte cultures to determine the sensitivity of this flow cytometry-based procedure to detect aneugenic agents. A comparison between the microscopic and the flow cytometry-based procedures for scoring polyploidy shows a strong agreement exists between the two methods. Treatments with two known aneugenic agents, griseofulvin, and paclitaxel (taxol), resulted in a dose-related increase in the mitotic index, aneuploidy, and polyploidy. In contrast, results from the treatments with two known clastogenic agents, mitomycin-C, and etoposide, show a dose-related decrease in the mitotic index with a slight increase in the frequency of hypodiploidy at concentrations that produce severe chromosomal breakage. There were no increases in hyperdiploidy and polyploidy observed. In conclusion, the reproducibility of the results obtained in this study indicates that this flow cytometry-based procedure for assessing numerical chromosomal effects in mitotic populations on the basis of DNA content is promising for the routine detection and characterization of aneugenic agents.