Methylation analysis of CIDE-A. (a) The region analysed by CoBRA and sequencing is shown with CpG dinucleotides numbered and shown in bold and BstUI restriction sites underlined. The positions of CoBRA primers are also shown, covering the region between -277 and -31 with respect to the transcription start site. (b) CoBRA results are shown with undigested (U) PCR product next to digested (D) PCR product for breast cancer cell lines and normal breast. (c) CoBRA results for primary breast tumours. (d) CoBRA results for breast tumour normal pairs. (e) Selected PCR products were cloned and sequenced. Individual alleles of each of the four samples shown are represented by a line, black and white circles represent methylated and unmethylated CpG dinucleotides respectively. The frequency of methylation within the amplified region for each sample is indicated by the methylation index (MI). (f) CIDE-A expression in normal breast tissue and re-expression in methylated breast cancer cell line MBA-MD-231 following the addition of 5-aza-2'deoxycitidine is shown.