Morphological transformation and chromosome aberrations produced by two hair dye components

A POSSIBLE carcinogenic hazard from hair dyes has been suggested recently by mutagenicity studies using the Salmonella tester strains developed in Ames' laboratory^1,2. We had previously found a good correlation between mutagenicity produced by specific cigarette smoke condensate fractions in the Salmonella mutagenesis system³ and oncogenic transformation in the mouse C3H/10T1/2CL8 cell line⁴ developed in Heidelberger's laboratory. I have therefore studied transformation in this cell line after exposure to two hair-dye components, 2-nitro-p-phenylenediamine (2-NPPD) and 4-nitro-o-phenylenediamine (4-NOPD), both of which had been found to be highly mutagenic in the tester strain TA1538. Although 2-NPPD has greater mutagenic capacity in the presence of a microsomal activation system¹, I thought that 2-NPPD might be able to transform C3H/10T1/2CL8 cells since there is sufficient microsomal activity to convert certain carcinogens such as polycyclic hydrocarbons to their active form(s)⁶. Both 2-NPPD and 4-NOPD were found to produce significant morphological transformation in the C3H/10T1/2CL8 cell line. In addition, in view of the reported correlation between specific chromosome changes and the expression of malignant transformation^7,8 and the fact that known carcinogens rapidly produce chromosome aberrations⁹, I sought and found chromosome changes after treatment with these hair dye components.