ZIC1 gene expression is controlled by DNA and histone methylation in mesenchymal proliferations

RNA and protein analysis revealed the consistent upregulation of the neural transcription factors ZIC1 and ZIC4 in desmoid tumors and other fibroproliferative disorders. The 5′ flanking region of the ZIC1 promoter was unmethylated in desmoid tumor fibroblasts, while a hypermethylated ZIC1 promoter was found in human and mouse cell lines not expressing the gene. In addition, expressing cells showed a H3K4me2 at the ZIC1 promoter, whereas non-expressing cells showed higher levels of H3K9me2 in the same region. To our knowledge, this is the first report describing ZIC1 expression in mesenchymal proliferations and a role for DNA methylation in the control of ZIC1 expression.