抄録
Aneuploidy can have significant impact upon human health including reproductive problems and cancer. However, there is no test method currently that is widely used in routine screening assay for aneuploidy detection. In this study, in order to develop a routinely available screening assay, we evaluated the efficacy of our in vitro micronucleus (MN) test protocol. The MN test with a Chinese hamster lung cell line (CHL/IU) without cytochalasin B was conducted on seven chemicals, namely, five potential aneugens which induced polyploidy in the in vitro chromosomal aberration (CA) test and whose mechanism of action is unknown, and two well-known aneugens (colcemid and diethylstilbestrol). Besides micronucleated (MN) cells (parameter widely used for detecting clastogens and aneugens in the existing protocols), polynuclear (PN) cells and mitotic (M) cells were used for assessment of aneuploidy induction. In vitro CA tests were also performed to compare with the MN test. All seven chemicals induced polyploidy in the CA tests. While three chemicals significantly increased the frequency of MN, PN, and M cells in the MN tests, the other four chemicals increased only the frequency of PN cells. Based on the patterns of appearance of aberrant cells induced by test chemicals, the seven chemicals could be classified into two groups. It is thought that the difference in the patterns between the two groups reflects the difference in mechanisms of action. Our results indicate a possibility that aneuploidy and polyploidy can be distinguished by the analysis of patterns of appearance of aberrant cells in the MN test. We have concluded that our MN test protocol, easier-to-perform, and more sensitive for detecting potential aneugens as compared with the existing protocols, may be useful for routine screening.
