Figure 1.

Representative methylation analysis of DL samples from BRCA carriers in whom aberrant methylation was found. (a) Hypermethylation of RAR-β found in ductal lavage (DL) samples from subjects 17, 11, 3 and 6. Replicate PCR experiments for subject 11, using DNA from the same duct, are shown to illustrate reproducibility. (b) Methylation analysis of HIN-1. Two different ducts for subject 1 are shown: the first is unmethylated (duct right 2a; see Figure 2) and the second shows hypermethylation of HIN-1 (duct right 1a). Subjects 11, 13 and 8 show aberrant methylation of HIN-1. In both panels, unmethylated control samples consisted of 1 mg/ml solutions of human sperm DNA (HSD), and methylated controls were 1 mg/ml solutions of DNA extracted from the MDA-MB-231 breast cancer cell line (231). Marker used is a 123bp DNA ladder - rungs represent 123bp, 246bp and 369bp. M, methylated; U, unmethylated.