Figure 2. Methylation of GLCE promoter-associated CpG islands in human breast tumors and cancer cell lines. (A) Schematic showing the CpG islands in the GLCE promoter region. Location of methylation-specific and bisulphite sequencing PCR primers are indicated by arrows. (B) Methylation-specific PCR for the GLCE promoter region. 300–328 - breast tumors, C and T, control and tumor breast tissues (match pairs from each patient); PC, positive PCR control; NC, negative PCR control; M, DNA marker; M and U, primers for methylated or unmethylated DNA sequences, respectively. (C and D) Bisulphite sequencing of breast tumors (C) and breast cancer cell lines MCF7 and T47D (D) using the BS1 primer pair. 300 and 301 patients, 7 different E. coli clones (1–7) were sequenced for each breast tumor or cell line, open and black circles are non-methylated and methylated CpG dinucleotides, respectively.