Potential carcinogenicity of aza-aromatic hydrocarbons: azabenz(a)anthracenes.

The potential carcinogenicity of 3 azabenz(a)anthracenes was determined in vitro. The 3 compounds tested were 1-, 2-, and 9-azabenz(a)anthracene. The initial assay was chemical carcinogen-induced enhancement of anchorage-independent survival of Rauscher leukemia virus-infected Fischer rat embryo cells, 2FR(4)50 (2FR4). Cells treated with 2- and 9-azabenz(a)anthracene showed dose-dependent increased survival. After continued subculturing, the surviving cells from 2- and 9-azabenz(a)anthracene-treated cultures displayed morphological transformation and ability to grow in semi-solid medium. Mock-treated controls and I-azabenz(a)anthracene-treated cultures did not show either of these properties. These data suggest that certain azabenz(a)anthracenes are potential carcinogens.