The role of DNA damage by reactive nitrogen species in carcinogenic process caused by oncogenic K-ras mutation.

K-ras突变在人类肺癌中经常观察到。另一方面，人们认为癌变是一个多步骤的过程，有10多个基因发生突变。在本研究中，8-硝基鸟嘌呤和8-oxodG在致癌性K-ras引起的肺腺癌中明显形成，无炎症反应。有报道称，8-硝基鸟嘌呤和8-oxodG可引起突变。这表明致突变性8-硝基鸟嘌呤和8-oxodG的积累有助于促进K-ras突变引发的肺癌发生。

K-ras mutations are frequently observed in human lung cancer. On the other hand, it is considered that carcinogenesis consists from multi-step process with mutations in more than 10 genes. In this study, 8-nitroguanine and 8-oxodG was apparently formed in lung adenocarcinoma caused by oncogenic K-ras, withoutinflammation. It is reported that 8-nitroguanine and 8-oxodG can cause mutations. These suggest that the accumulation of mutagenic 8-nitroguanine and 8-oxodG contributes to promotion of lung carcinogenesis initiated by K-ras mutation.