Assessing the predictiveness of the Syrian hamster embryo cell transformation assay for determining the rodent carcinogenic potential of single ring aromatic/nitroaromatic amine compounds.

The pH 6.7 Syrian hamster embryo (SHE) cell transformation assay was used to test the morphological transformation potential of 5 rodent carcinogenic single ring aromatic/nitroaromatic amine compounds: 2-amino-4-nitrotoluene, 2,4-diaminotoluene, 2,4-dinitrotoluene, o-anisidine hydrochloride, and o-toluidine; and 5 noncarcinogenic single ring aromatic/nitroaromatic amine compounds: 2,6-diaminotoluene, 2,4-dimethoxyaniline hydrochloride, 4-nitro-o-phenylenediamine, p-phenylenediamine dihydrochloride, and HC Blue No. 2. All 5 rodent carcinogens produced significant morphological transformation in a dose-responsive manner. None of the 5 noncarcinogens yielded significant transformation at any of the doses tested. Therefore, the concordance between the pH 6.7 SHE cell transformation assay and rodent carcinogenicity for these 10 single ring aromatic/nitroaromatic amine compounds is 100%. In contrast, the concordance between the standard SHE cell transformation assay and rodent carcinogenicity for 13 single ring aromatic/nitroaromatic amine compounds was 62%. For 5 aromatic/nitroaromatic amine compounds which were tested in both standard and pH 6.7 SHE cell transformation assays (i.e., a subset of the above two databases), the concordance between the standard SHE cell transformation assay and the rodent bioassay was 40%, while the concordance between the pH 6.7 SHE cell transformation assay and the rodent bioassay was 100%. This relatively high concordance between the pH 6.7 SHE cell transformation assay and rodent bioassay results demonstrates the utility of the pH 6.7 SHE cell transformation assay for predicting the rodent carcinogenic potential of single ring aromatic/nitroaromatic amine compounds.