Hypermethylation of the SEPT9_v3 promoter occurs in human breast primary carcinomas. (A) Cell lines were treated with 5-aza-2'-deoxycytidine, and SEPT9_v3 mRNA was quantified. Representative cell lines with hypermethylation (left graph) and hypomethylation (right graph) of the SEPT9_v3 promoter region are displayed. U: untreated cells; T: treated cells. (B) SEPT9_v3 promoter region activity. Top: Location of tested luciferase fragments relative to the DMR. Bottom: Quantification of these fragments via luciferase reporter assay. (C) Supervised clustering of MassARRAY DNA methylation profiles in human primary adenocarcinomas, matching tumor-free areas and normal breast tissues. Right graph: Average levels of DNA methylation between tumors and tumor-free matching samples show a statistically significant difference.