1-nitropyrene induces elevated expression of oncogenes and tumor suppressor genes 24 hours after treatment in CBA/Ca mice

In an earlier experiment we found that 1-nitropyrene treatment causes an in crease in the expression of cer tain onco/suppressor genes in different org ans of CBA/Ca mice. In order to further study the kinetics and significance of these gene expression changes, we determined the effect of 1-nitropyren e treatment on the expression of c-myc, p53, Ha-ms, N-ras, and Ki-ras genes , 24 hours after treatment. Expression of the ras family did not change dur ing the studied interval, while elevated expression of c-myc and p53 genes was observed in the spleen, bone marrow and lymph nodes (only c-myc in the latter). The results suggest a different pattern for the involvement of the was genes in I-nitropyrene-caused carcinogenesis, and also under lines the differences in the organ specificity of chemical carcinogens in humans and in experimental animals. In the present study, we also confirmed the in vi vo applicability of early gene expression changes as biomarkers of carcinog enic exposure.