To study the expression and role of adhesion molecules in normal salivary g
lands and their tumors, we have studied simultaneously the expression of E-
cadherin, and associated cytoplasmic proteins, alpha-catenin and beta-caten
in. Paraffin sections were evaluated using the streptavidin biotin peroxida
se complex (SBPC) method for E-cadherin, and the SBPC method with tyramide
signal amplification (TCA) for alpha- and beta-catenin.
Normal submandibular (n = 10), parotid (n = 4) and oral minor glands (n = 4
) showed cell membrane staining for E-cadherin and a positive reaction in i
ntercalated and striated ducts for alpha- and beta-catenin. Pleomorphic ade
noma (n = 17) showed cell membrane staining for E-cadherin and alpha-cateni
n in luminal and non-luminal cells, but were negative for beta-catenin. E-c
adherin was also focally or irregularly positive in modified myoepithelial
cells. Warthin's tumors (n = 4) expressed E-cadherin only and were negative
for alpha- and beta-catenins. Papillary adenocarcinoma (n = 4) showed pred
ominant staining for E-cadherin, with no expression in the other tumor cell
s. Adenoid cystic carcinoma (n = 4) showed only cell membrane positivity fo
r E-cadherin. with an absence of alpha- and beta-catenins in the luminal ce
lls. Non-luminal tumor cells of adenoid cystic carcinoma were negative for
beta-cadherin and positive for alpha- and beta-catenins. The results were c
oncluded as follows, 1) there was uniform cell membrane staining for E-cadh
erin in normal and benign tumor epithelium, but alpha- and beta-catenins sh
owed different expression and heterogeneous localization, 2) loss of E-cadh
erin reactivity was seen in malignant lesions, 3) there was no correlation
between the distribution of E-cadherin, alpha-catenin and beta-catenin in b
enign or malignant tumors of salivary gland origins. The results show varia
bility and heterogeneous expression for E-cadherin, alpha- and beta-catenin
s in salivary gland tumors.