Analysis of the methylation status of the HA-1 promoter in cell lines and primary breast cancers. Genomic DNA extracted from various HA-1^pos and HA-1^neg tumor cell lines, fibroblasts, and primary breast cancers was subjected to sodium bisulfite treatment. (A) A long (−341 to +19) and a short (+47 to +222) DNA fragment were amplified by PCR and were subsequently analyzed by sequencing; y-axis indicates percentage of methylated cytosines in 7 to 10 independent DNA clones per cell line; x-axis, position of the CpG dinucleotides with respect to the ATG translation start site (+1). (B) COBRA of laser-microdissected primary breast cancer samples. BC1 to BC10 indicate invasive breast cancers; M, methylation.