In vitro cell transformation screening of 4 toluene diamine isomers.

2,4-, 2,5-, 2,6- and 3,4-Toluene diamine (TDA) were tested for their ability to enhance the transformation of primary hamster embryo cells (HEC) by Simian adenovirus 7 (SA7) when administered either prior to or after virus inoculation and for their ability to transform secondary HEC. 2,4-TDA was inactive when given prior to SA7, but active if given after. 2,5-TDA was active in both protocols. 2,6-TDA was marginally active if administered before virus and was the most active of the isomers when administered after virus. 3,4-TDA was the most active compound when added prior to SA7, and was also active when given after virus. All the isomers were capable of producing good dose--responses and absolute increases in the number of virus-transformed foci per dish in one or both of the experimental regimens. Each isomer chemically transformed secondary HEC but good dose--responses were rare, and none of the chemicals were active in more than 50% of the 5 or 6 separate tests performed on each.