ABSTRACT
BACKGROUND: Alterations in intercellular and cell-extracellular matrix connections contribute to tumour development. This study investigates the expression of specific cell adhesion molecules (CAMs) in salivary gland tumors (SGTs). METHODS: Formalin-fixed, paraffin- embedded tissue specimens of different types of 34 benign and 31 malignant SGTs and normal salivary glands were studied using Envision/HRP immunohistochemical technique for Desmoglein-2 (Dsg-2), beta4-integrin, CD44s and ICAM-1. Intensity of staining was evaluated in a semi-quantitative manner. Results were analyzed using Kendall's τ and Spearman's ρ as correlation criteria. RESULTS: Dsg-2 in intercellular space, beta4-integrin in cell-basal membrane, and CD44s in both types of contacts were strongly expressed in normal acinar and ductal cells, whereas ICAM-1 was expressed only at the endothelium and sparse stromal cells and monocytes. Strong correlation was found between Dsg-2 expression in adenomas and controls and between adenocarcinomas and controls. In adenomas, a distinct cytoplasmic presence of Dsg-2 was observed in addition to the usual membranous expression, with decreased expression in comparison with normal tissue. In malignant SGTs, Dsg-2 expression was absent. In most SGTs, beta4-integrin was expressed also with a distinct pattern, involving the cytoplasm and the unpolarised membrane, while CD44 was found only on the membrane. Strong correlation between beta4-integrin expression in adenomas and controls was noted, while CD44 expression was found to be correlated significantly between adenocarcinomas and controls (p < 0.001). Regarding ICAM-1, its expression was found increased in adenomas, with non-specific distribution in malignant SGTs and strong correlation between the histological subtypes and controls (p < 0.001). CONCLUSION: The different expression profile of CAMs in SGTs could possibly suggest a role on their pathogenesis, representing a model of how neoplastic cells can take advantage of normal tissue architecture and cell-extracellular matrix interactions.
ABSTRACT
The study of the expression of cell adhesion molecules (CAMs), E-cadherin, desmoglein-2, beta4-integrin, HCAM (CD44s) and ICAM-1 in Warthin's tumours. Twenty formalin--fixed, paraffin--embedded parotid Warthin's tumours were studied using an Envision/HRP immunohistochemical technique. Beta4-integrin was strongly expressed in all cell-basement membrane and intercellular contacts of the epithelium, E-cadherin and desmoglein-2 in cell-cell contacts, but not in basal cell-basement membrane connections and on columnar cells' luminal surfaces, HCAM (CD44s) in intercellular contacts of both luminal (mainly), basal cells and also in the periphery of monocytic-lymphocytic stroma, and ICAM-1 was weak to moderate expressed in both luminal and basal epithelial cells and strongly in the germinal lymphocytic centres. CAM expression suggests a bilayered excretory ductal structure of the neoplastic epithelium in Warthin's tumour, as a result of hyperplastic process of the glandular epithelium that interacts with the excessive lymphoid tissue of the stroma.
