Use of the orthogonal design method to study the synergistic effects of asbestos fibres and 12-O-tetradecanoylphorbol-13-acetate (TPA) in the BALB/3T3 cell transformation system

An orthogonal design method was used to study the transformingeffects of chrysotile and crocidolite asbestos fibres in BALB/3T3cells. Three experiments, designed by tables L₉ (3⁴), L₈ (2⁷)and L₆ (3¹ x 2²) of the orthogonal method respectively, wereperformed separately. The results indicate exponential reductionsin survival of treated cells concomitant with a linear increasein exposure concentrations from 0.1 to 10.0 µg/cm², andthat chrysotile was more toxic than crocidolite; the total transformationfrequency was significantly increased with both chrysotile andTPA concentrations. There was synergism between chrysotile andTPA in sequential treatment, which suggests that chrysotileis an initiator and has a complete transforming effect at 10.0µg/cm². Crocidolite only has an initiating-like effectwithin the dose range of 0.1 – 10.0 µg/cm², andno synergistic effect when associated with TPA. ¹Present address: Department of Occupational Health, Shanghai Medical University, Shanghai 200032, People's Republic of China²To whom correspondence should be addressed.