e2f1 gene is a new member of Wnt/β-catenin/Tcf-regulated genes

HDAC inhibitors induce cell cycle arrest of E1A + Ras-transformed cells accompanied by e2f1 gene down-regulation and activation of Wnt pathway. Here we show that e2f1 expression is regulated through the Wnt/Tcf-pathway: e2f1 promoter activity is inhibited by sodium butyrate (NaB) and by overexpression of β-catenin/Tcf. The e2f1 promoter was found to contain two putative Tcf-binding elements: the proximal one competes well with canonical Tcf element in DNA-binding assay. Being inserted into luciferase reporter vector, the identified element provides positive transcriptional regulation in response to β-catenin/Tcf co-transfection and NaB treatment. Thus we have firstly demonstrated that e2f1 belongs to genes regulated through Wnt/β-catenin/Tcf pathway.