Figure 2.

p53, p16, and TERT nuclear expression by immunohistochemistry in the multistep progress to lung cancer. (A) Normal lung epithelial cells showed low levels of nuclear protein expression for p53, p16, and TERT. (B and C) Hyperplastic bronchiolar (B) and alveolar (C) cells showed a significant increase for p53, p16, and TERT nuclear immunostaining. (D) DB at 10 to 12 months showed a higher percentage of positive nuclear cells for p53 and TERT. However, p16 was significantly decreased in these advanced preneoplastic lesions. (E and F) p53 and TERT overexpression was commonly observed in AC (E) and SCC (F), whereas p16 overexpression was observed in SCC (F) and in a subset of more fibrotic AC. Loss of p16 protein expression (< 25% positive nuclei) was detected in 44% of AC (p16; E). Counterstaining by Harris hematoxylin. Original magnifications, × 420 (p53-TERT; B) (p16; D, E, and F); × 560 (p16; B); × 700 (A and C) (p53-TERT; D).