Short-term effects of 1-nitropyrene on chromosomes and on oncogene/tumor suppressor gene expression in vivo

In order to establish an animal model testing the effects of 1-nitropyrene in vivo at the oncogene level, we investigated the early biological effects of 1-nitropyrene in mice. The treatment of 6-8 week-old CBA/Ca mice with a single 30 μmol/kg body weight dose of 1-nitropyrene caused a significant increase in chromosome aberrations 48 hours after exposure. The aberrations were mainly of the euploid type. We also found elevated expression of the Ha-ras oncogene in the isolated total cellular RNA from the liver, lung, kidney, spleen and thymus. The highest increase was seen in the lung and it was also high in the spleen and in the thymus. There was a higher increase in the males than in the females in all organs. In this study we confirmed that early genetic alterations such as oncogene expression, can be examined not only in vitro, but also in vivo experiments.