Morphological transformation of BALB/3T3 mouse embryo cells in vitro by vomitoxin

The transforming potential of vomitoxin, a trichothecene mycotoxin produced on cereal grains by fungi of the genus Fusarium, was assessed using mouse embryo BALB/3T3 A31-1-1 cells. Cells grown in Eagle's basal medium with Earle's salts supplemented with 7.5% foetal bovine serum were treated with highly purified vomitoxin, which was dissolved in distilled water and filter-sterilized. Assays were conducted using cells from three different passages at dose levels ranging from 0.1 to 1.6 microgram/ml. The treatment time was 48 hr and the highest dose levels tested produced approximately 10% survival as determined by in situ cell counts. Distilled water and 3-methylcholanthrene (5.0 micrograms/ml) were used as the vehicle and positive controls, respectively. Of the 20 dishes examined per dose group, the numbers of type III foci were 0-1 in the solvent control, 12-15 in the positive control and 0-9 in the treated groups. Comparison of the three assays showed that the level of response varied with passage number. Of the three passages of cells tested-passage numbers 6, 8 and 9 (p6, p8 and p9)--passage-9 cells produced the strongest positive effect.