Expression and promoter methylation of DACT1 in breast cancer. (A) DACT1 expression in human normal adult and fetal tissues as detected by semiquantitative RT-PCR, with GAPDH as a control. (B) Schematic structure of the DACT1 promoter CpG island (CGI). Exon 1 (gray rectangle), CpG sites (short vertical lines), transcription start site (curved arrow), and MSP sites analyzed are indicated. (C) DACT1 was silenced by promoter methylation in breast cancer cell lines, but readily expressed in normal breast tissues. (D) Pharmacologic demethylation with Aza combined with TSA (A+T) restored DACT1 expression in breast cancer cell lines. M, methylated; U, unmethylated.