Peroxiredoxin I is overexpressed in oncocytic lesions of salivary glands

Background: Oncocytic lesions, particularly frequent in the salivary glands, are characterized by cells with an atypical accumulation of mitochondria. This accumulation has been recognized as a compensatory mechanism to intrinsic functional defects of these organelles, resulting in energy production impairment and increased generation of reactive oxygen species (ROS), including hydrogen peroxide (H(2)O(2)). Peroxiredoxin I (Prx I) is a H(2)O(2) scavenging protein and the expression of its yeast homolog was reported to be influenced by mitochondrial function. Methods: In this study, we evaluated Prx I expression in oncocytic lesions of salivary glands by immunohistochemistry. Results: Our results showed that Prx I is overexpressed in oncocytes regardless of the salivary gland lesion where they appear. Conclusions: These results suggest that Prx I expression in oncocytes is related to its ability to decompose mitochondrial-derived H(2)O(2) and that it could provide to the cells a protective role in an environment that, by continuously producing potential DNA-damaging ROS, predisposes to genome instability and cellular transformation.