| [ Summary ] |
Recently, chronic inflammation, induced by infection, has been postulated to be a risk factor for various forms of cancer. Reactive oxygen and nitrogen species are considered to play a key role in inflammation-mediated carcinogenesis. We examined 8-nitroguanine and 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG) formation in the liver of hamsters infected with Opisthorchis viverrini (O. viverrini), a liver fluke causing intrahepatic cholangiocarcionoma. Notably, a double immunofluorescence study revealed that formation of 8-nitroguanine and 8-oxodG increased in the epithelium of bile ducts depending on the frequency of O. viverrini infection. In gastritis patients with Helicobacter pylori (H. pylori) infection, the level of 8-nitroguanine in the gastric gland epithelium was significantly higher than in those without H. pylori infection. Interestingly, H. pylori eradication attenuated 8-nitroguanine formation in the gastric epithelium. Moreover, in patients with hepatitis C viral infection, 8-nitroguanine formation was observed in hepatocytes. These results suggest that 8-nitroguanine can be utilized as a promising biomarker to evaluate the cancer risk and efficacy of treatment for inflammation-related diseases. Here in we discuss the role of 8-nitroguanine in inflammation-mediated carcinogenesis. |