Reduced membranous and ectopic cytoplasmic expression of DSC2 in esophageal squamous cell carcinoma: an independent prognostic factor

Desmocollin 2, a desmosomal component, is a key membrane glycoprotein critically involved in cell-cell adhesion and the maintenance of normal tissue architectures in epithelia. Reports exploring the link of desmocollin expression to cancers are limited. The aim of this study was to investigate the expression of desmocollin 2 in esophageal squamous cell carcinoma and, in particular, to determine the extent to which the patterns of desmocollin 2 expression correlated with the clinical parameters. Desmocollin 2 expression was evaluated in 308 cases of esophageal squamous cell carcinoma using immunohistochemistry. Western blotting and reverse transcriptase polymerase chain reaction were performed to characterize the relative expression levels of desmocollin 2 isoforms. The results indicated that desmocollin 2 expression was reduced significantly in esophageal cancer in both protein and messenger RNA levels and that this reduction was associated with poor survival (P = .011). The expression of desmocollin 2 was prominent in normal esophageal epithelia and highly differentiated esophageal tumors, but was reduced or absent in poorly differentiated tumor specimens. Furthermore, in 74.7% of tumor tissues, desmocollin 2 immunoreactivity displayed an abnormal cytoplasmic localization that was correlated with poor tumor differentiation (P < .001), regional lymph node metastasis (P < .001), pathologic tumor-node-metastasis stages (P < .001), and poor prognosis (P = .048). Multivariate analysis showed that desmocollin 2 expression level was an independent prognostic factor for esophageal squamous cell carcinoma. These data suggest that desmocollin 2 is involved in the transformation and development of esophageal tumors and that desmocollin 2 expression level and intracellular localization may serve as a predictor for patient outcomes.