Down- regulation of BRD7 in NPC cells is due to partial methylation of BRD7 promoter. (A) Map of the methylation- and unmethylation-specific primer in BRD7 promoter region. (B) PCR amplification of BRD7 promoter region by using methylation- and unmethylation-specific primer. PCR product was size-fractionated on agarose gels and bands visualized by ethidium-bromide staining of the gels. The presence of a PCR band in the lane "M" indicates methylated genes, while the presence of a PCR band in the lane "U" indicates unmethylated genes. (C) Detection of BRD7 mRNA expression in the cell lines by RT-PCR.