NF-kappaB Regulates Redox Status in Breast Cancer Subtypes.

Oxidative stress (OS) is an indispensable condition to ensure genomic instability in cancer cells. In breast cancer (BC), redox alterations have been widely characterized, but since this process results from a chain of inflammatory events, the causal molecular triggers remain to be identified. In this context, we used a microarray approach to investigate the role of the main pro-oxidant transcription factor, nuclear factor-kappa B (NF-κB), in gene profiles of BC subtypes. Our results showed that NF-κB knockdown in distinct BC subtypes led to differential expression of relevant factors involved in glutathione metabolism, prostaglandins, cytochrome P450 and cyclooxygenase, suggesting a relationship between the redox balance and NF-κB in such cells. In addition, we performed biochemical analyses to validate the microarray dataset focusing on OS and correlated these parameters with normal expression or NF-κB inhibition. Our data showed a distinct oxidative status pattern for each of the three studied BC subtype models, consistent with the intrinsic characteristics of each BC subtype. Thus, our findings suggest that NF-κB may represent an additional mechanism related to OS maintenance in BC, operating in various forms to mediate other important predominant signaling components of each BC subtype.