Primary hamster embryo cells were treated with various chemical carcinogens before, or after, inoculation with an oncogenic adenovirus, simian adenovirus 7. The viral transformation frequency was increased from 3- to 10-fold by treatment with methyl methanesulfonate, methylazoxy-methanol acetate, N-methyl-N′-nitro-N-nitrosoguanidine, and N-acetoxy-acetylaminofluorene; but no increase was demonstrated when cells were treated with N-nitrosodiethylamine, N-nitrosodimethylamine, or 2-acetylaminofluorene.

The frequency of viral transformation increased linearly with chemical concentration until a maximum level was reached; however, higher concentrations decreased the transformation frequency relative to that observed with lower doses.

It is suspected that the chemical carcinogens enhance viral transformation by interacting directly with the host cells, rendering them more susceptible to transformation by virus.


The work upon which this publication is based was performed pursuant to Contract No. NIH-NCI-71-2164 with the National Cancer Institute, Department of Health, Education, and Welfare.

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