Inflammation-induced oxidative stress in breast cancer patients.

Inflammation induced by cytokines has been linked to increased production of reactive oxygen species and breast cancer development. The aim of this study was to evaluate the influence COX-2, IL-1β, IL-8, and TNF-α gene expressions on DNA damage, and investigate a possible link between these factors with neoplastic process. The mRNA expression was measured by real-time PCR, and the DNA damage was analyzed by single-cell gel electrophoresis (comet assay). Our data indicated a significant increase on inflammatory gene expression in tumor tissues compared with normal tissue, and it was also associated with undifferentiated grade patients. Moreover, the results showed that the higher levels of DNA damage were observed among tumor tissue samples. Taken together, the findings presented in this study highlight the relevance of inflammation-induced oxidative stress in breast carcinogenesis.