Figure 1

SSCP and sequencing analysis of the ER-α A908G mutation in invasive breast tumors. (a) Single-strand conformational polymorphism (SSCP) analysis showing the band shift characteristic of the estrogen receptor-α (ER-α) A908G mutation in ductal breast tumor 52 and in the positive control tissue MN31 (Pos). Tumors 51 and 53 to 55 show the wild-type SSCP pattern, as does the MCF-7 negative control cell line (Wt). Und is the undenatured wild-type control. (b) ³³P-Cycle sequencing analysis confirming the presence of the ER-α A908G mutation in breast tumors 52, 15, 28, 313 and 341, as indicated by the upper arrow (A→G). Tumor 87 shows only wild-type ER-α. Note that tumor 52 also carried a second mutation, a deletion of A in codon 302, indicated by the lower arrow (del A), which seems to be in the allele exhibiting the A908G mutation in codon 303.