Fig. 10.

Dkk1 overexpression associates with cellular senescence in vivo. A: scatter graph of quantitative RT-PCR data for p16 mRNA expression in distal and proximal esophageal mucosa of esophagitis patients (n = 15). Results were normalized to β-actin expression (P ≤ 0.05 by paired t-test). B: correlation of Dkk1 mRNA expression with p16 mRNA expression in distal esophageal mucosa of esophagitis patients. (r = 0.958, P ≤ 0.00001 by Pearson's correlation test). C and D: immunohistochemistry for colocalization and Western blot analysis for coexpression of Dkk1 and p16 protein expression in esophageal biopsies of 3 esophagitis patients (1, 2, and 3). E: SA-β-Gal staining in healthy human esophageal mucosa and reflux esophagitis. Arrows, β-Gal-positive cells on the basal layer of esophageal mucosa with esophagitis. Barrett's metaplasia serves as control for positive SA-β-Gal activity. Images represent results from ≥3 different patients in each group.