Perinuclear and cytoplasmic distribution of desmoglein in esophageal squamous cell carcinomas

The desmosomal glycoproteins desmoglein (Dsg) and desmocollin (Dsc) are members of the cadherin family of cell adhesion molecules. They play an important role in epithelial adhesion. To observe the distribution pattern of Dsg in esophageal squamous cell carcinomas (SCC), immunohistochemical and immunoelectron microscopic analyses were performed. Immunohistochemically, normal esophageal squamous cells strongly expressed Dsg at the cell-cell boundaries, while moderately differentiated esophageal SCC cells showed a perinuclear distribution in addition to the cell boundary staining. At the ultrastructural level, the reaction product was concentrated at the desmosomes in the cell membrane region of normal epithelial cells, but was reduced at the membrane and found throughout the cytoplasm as well as in the surrounding outer nuclear envelope in SCC cells. These results demonstrate an aberrant distribution of Dsg in SCC cells. This may have important consequences for invasion and metastasis, as it may indicate loosened intercellular adhesion.