Figure 5. Concomitant activation mutation and gene amplification of PIK3CA in breast cancer.

A) Examples of PIK3CA amplification in five tumors are illustrated. Formatting of Figure 5A is the same as for Figure 1B. B) The mutation analysis for these five tumors is depicted. Two exons (10 and 21) of PIK3CA showed mutations. The tumors in Figures 5A and 5B are matched and displayed in the same order from top to bottom. The first tumor (at the top), which exhibits high-level copy number gain, lacks a PIK3CA mutation in both exons 10 and 21. The arrowheads in the first tumor mark the bases with the mutations, E545K (exon 10), H1047R (exon 21), and G1049R (exon 21), identified in other tumors. The positions of the mutations in these last four tumors are highlighted by black boxes, with the mutations labeled by the amino acid substitutions. C) Association of PIK3CA mutation and gene amplification are summarized here. On the left side, it displays a 2×2 contingency table showing the number of tumors in each of the four categories: copy number gain only; PIK3CA mutation only; copy number gain plus PIK3CA mutation; neither copy number gain nor PIK3CA mutation. On the right side, it displays a 2×2 contingency table showing only tumors with a PIK3CA mutation. Copy number gain is depicted in relation to type of PIK3CA mutation. The following four categories are included: copy number gain with an H1047R mutation; copy number gain with a non-H1047R mutation; an H1047R mutation without copy number gain: a non-H1047R mutation without copy number gain.