Figure 2.

Evaluation for PTEN and proteins in the PI3K/mTOR pathways in HNSCC samples. (A) HNSCC TMA slides (NIDCR) were analyzed for PTEN (IHC). PTEN immunoreactivity in the tissue array cores (n = 347) was classified into five groups: 0 (less than 10% stained cells), 1 (10–25%), 2 (25–50%), 3 (50–75%), and 4 (75–100%). (B) PTEN levels in well-differentiated (wd), moderately differentiated (md), and poorly differentiated (pd) tumors. Scores were represented as average of PTEN stain per differentiation group (error bar, SEM; ***P ≤ .001). Poorly differentiated tumors (pd) express significantly lower levels of PTEN than well-differentiated (wd) or moderately differentiated carcinomas (md). (C) Heat map generated from the IHC analysis of the indicated proteins in the tissue microarray. Unsupervised clustering analysis shows correlation between pAKT^Ser473, pS6, EGFR, pAKT^Thr308, and PTEN. Separation of clusters was indicated for the groups in which PTEN and pEGFR are co-expressed (A), whereas cluster A1 defines a subgroup of HNSCC lesions in which both proteins are decreased.