Nuclear, cytoplasmic, and stromal expression of ZEB1 in squamous and small cell carcinoma of the esophagus

Zinc finger E-box-binding homeobox 1 (ZEB1) is a transcriptional factor known to repress E-cadherin promoter and thus induce EMT. Expression of ZEB-1 has in numerous cancers been associated with aggressive disease and poor clinical outcome. Our aim was to investigate the expression of ZEB1 in esophageal squamous- and small-cell carcinomas. Immunohistochemical staining was performed on tissue sections obtained from 151 patients with esophageal squamous cell carcinoma (ESCC) and 25 patients with primary small-cell carcinoma of the esophagus (PSCCE). Semi-quantitative analysis, and thus statistical analysis, has been accomplished on the samples. Immunohistochemistry revealed ZEB1 expression in the cytoplasm (64.9% of cases), in nuclei (11.3% of cases) and in tumor stroma (80.1% of cases) of ESCC. In PSCCE only nuclear staining (88.0% of cases) was observed. Weak cytoplasmic expression of ZEB1 in ESCC was associated with longer survival. Immunohistochemical evaluation of ZEB1 cytoplasmic expression in ESCC may have clinical prognostic value, but further studies are needed to fully understand the function as well as potential clinical and therapeutic implications of ZEB1 expression in cancers.