The interaction of ionizing radiation and food pyrolysis products in producing oncogenic transformation in vitro.

Short term cultures of golden hamster embryo cells were exposed to X-irradiation and/or to 3-amino-1-methyl-5H-pyrido[4,3,-b]indole (Trp-P-2), a pyrolysis product of GL-tryptophan. Oncogenic transformation was scored following treatment with radiation and the pyrolysate, alone or in combination. Pre-treatment of the cells with 50 rad or 150 rad and subsequent exposure to 0.5 microgram/ml Trp-P-2, resulted in a higher transformation frequency as compared to that observed following exposure to the single agents. The enhanced frequency was related to the absorbed dose of radiation. The data suggest a synergistic interaction between X-rays and the pyrolysis product in their oncogenic action.