Abstract
Cancer antigen 125 (CA125), encoded by the mucin 16 cell surface associated (MUC16) gene, has been widely used as a biomarker for ovarian cancer (OC) screening. However, it has yet to be elucidated as to why its levels increase with tumor progression as well as with certain other non-malignant conditions. Based on our knowledge of the inflammatory microenvironment (IME) in OC, HEY cells were treated with several inflammation-associated factors as well as their antagonists, and it was observed that inflammation-associated factors upregulated MUC16 gene expression. Considering the role of nuclear factor (NF)-κB in the inflammatory signaling network and our previous research on OC, chromatin immunoprecipitation was performed, and it was observed that activated NF-κB bound to the MUC16 gene promoter and enhanced its expression, thereby elevating secreted CA125 levels. These findings demonstrated that IME and MUC16 gene expression were associated in OC, partly elucidating the role of IME in tumor progression, explaining the elevated serum CA125 levels in some non-malignant conditions, and confirming IME as a potential target for OC therapy.