Induction of chromosome aberrations by fusarium T-2 toxin in cultured human peripheral blood lymphocytes and Chinese hamster fibroblasts.

T-2 toxin is an important representative of trichothecenes produced by various species of imperfect fungi, mainly Fusarium genus. It is a naturally occurring toxin that can cause severe diseases in human and animals. No definite data demonstrating the carcinogenic potential of T-2 toxin had been reported up to now. We demonstrated that T-2 toxin reproducibly induced chromosomal structural aberrations both in cultured human peripheral blood lymphocytes as well as in V79 Chinese hamster fibroblasts. The mean percentage of cells with aberration of human lymphocytes from normal individuals induced by T-2 toxin is 49-fold (9.8%) of the mean percentage of corresponding control cultures without T-2 toxin (0.2%). T-2 toxin induced chromosome type (76%) as well as chromatid type (24%) of aberrations; among them, acentric fragment (46%) was the most common type, and chromatid gap, deletion, and chromosome gap were the next most common. T-2 toxin can induce aberrations in cells at different phases of the cell cycle. There are definite dose-effect relationships within a certain range of dosage of T-2 toxin in experiments with both human peripheral blood lymphocytes and V79 cells. T-2 toxin exhibited three types of effects on cells, namely, mitogenic at lowest concentration, clastogenic (chromosome aberration) at median concentration, and cytotoxic at higher concentration. The dose-effect curves of these three effects are partly overlapping. There is some interindividual difference in sensitivity of response for the clastogenic effect of T-2 toxin, but no resistant individual was observed. Sex or age effect was not observed. The above results suggest that T-2 toxin has carcinogenic potentials. The dosage of aflatoxin that can induce chromosomal aberration of human peripheral blood lymphocytes is thousands-fold of the dosage of T-2 toxin as shown in this report. T-2 toxin might have more hazardous potentials than had been previously considered. The carcinogenic potential of T-2 toxin and related trichothecenes and their possible roles in carcinogenesis of upper gastrointestinal (G.I.) tract cancers need to be further investigated.