Figure 1

Proteomic and transcriptomic signatures of PI3K signaling are associated in ER+ breast tumors with lower ER and PR levels and the luminal B subtype. (a) Heat map of PI3K proteomic signature proteins in 429 ER⁺ human breast tumors, along with corresponding patterns for ER and PR (blue ER on the color scale meaning lower levels, although still present) and intrinsic molecular subtype association (luminal A versus luminal B). PI3K protein score is the sum of the phosphoprotein levels of Akt, mTOR, GSK3, S6K, and S6, minus the total levels of pathway-inhibitor PTEN. Tumors are ranked from low to high PI3K score, where a high PI3K score indicates high pathway activity. (b) PI3K transcriptomic (that is, mRNA) signature genes in 226 ER⁺ breast tumors (from van de Vijver et al.), along with ER and PR mRNA; tumors are ranked from low to high PI3K mRNA score. (c) Spearman's correlations between PI3K score and ER/PR in multiple expression-profiling datasets (four transcriptomic, one proteomic). For proteomic dataset, PI3K protein score and ER/PR protein levels were analyzed; for mRNA datasets, PI3K mRNA score and ER/PR mRNA. (d) In each of the five expression datasets, the average PI3K score in ER⁺ tumors of the luminal B subtype was compared with the average in ER⁺ tumors of the luminal A subtype by t test.