Desmoglein 3 (DSG3) is a calcium-binding transmembrane
glycoprotein component of desmosomes in vertebrate epithelial cells. Desmosomes
are cell-cell junctions between epithelial, myocardial, and certain other cell
types. Currently, three desmoglein subfamily members have been identified and
all are members of the cadherin cell adhesion molecule superfamily. These
desmoglein gene family members are located in a cluster on chromosome 18. This
protein has been identified as the auto antigen of the autoimmune skin
blistering disease pemphigus vulgaris. Lung studies have shown that DSG3 had a
sensitivity and specificity of 83% and 100% respectively, in detecting squamous
cell carcinoma (SqCC) versus adenocarcinoma. Thus, DSG3 is a first class marker
for lung SqCC and can be a useful ancillary marker to separate SqCC from other
subtypes of lung cancer. Other studies have shown that DSG3 expression in Lung
SqCC indicated a poor prognosis in lung cancers and portends a more aggressive
clinical outcome.