Effect of 3-aminobenzamide on the induction of toxicity and transformation by ethyl methanesulfonate and methylcholanthrene in BALB/3T3 cells.

3-Aminobenzamide, a potent inhibitor of nuclear poly ADP-ribosyl synthetase, was tested for its ability to alter the toxic and/or transforming effects of ethyl methanesulfonate, methyl methanesulfonate and 3-methylcholanthrene in BALB/3T3 clone A31-1 cells. 3-Aminobenzamide enhanced the toxic effects of both ethyl methanesulfonate and methyl methanesulfonate in a dose dependent manner, but had minimal effects on 3-methylcholanthrene induced toxicity. Similarly, 3-aminobenzamide greatly enhanced ethyl methanesulfonate induced transformation while failing to enhance the transformation of BALB/3T3 clone A31-1 cells by 3-methylcholanthrene. These results stress the importance of poly ADP-ribosyl synthetase in repair of DNA damage and the chemical induction of transformation in vitro.