Development of a micronucleus test using the EpiAirway™ organotypic human airway model

The use of organotypic human tissue models in genotoxicity has increased as an alternative to animal testing. Genotoxicity is generally examined using a battery of in vitro assays such as Ames and micronucleus (MN) tests that cover gene mutations and structural and numerical chromosome aberrations. At the 7th International Workshop on Genotoxicity Testing, working group members agreed that the skin models have reached an advanced stage of maturity, while further efforts in liver and airway models are needed [Pfuhler et al., Mutat. Res. 850–851 (2020) 503135]. Organotypic human airway model is composed of fully differentiated and functional respiratory epithelium. However, because cell proliferation in organotypic airway models is thought to be less active, assessing their MN inducing potential is an issue, even in the cytokinesis-blocking approach using cytochalasin B (CB) [Wang et al., Environ. Mol. Mutagen. 62 (2021) 306–318]. Here, we developed a MN test using EpiAirway™ in which epidermal growth factor (EGF) was included as a stimulant of cell division.

EpiAirway (AIR-100), Aneugen, Clastogens, EGF, TEER, adenylate kinase (AK), micronucleus assay, binculeated cells, cytochalasin B (CB), mitomycin C (MMC), methanesulfonate (MMS), colchicine (COL), replication index (RI), cytokinesis- block proliferation index (CBPI)

cytochalasin B, mitomycin C, methanesulfonate, colchicine