Salivary gland neoplasms comprise a heterogeneous group of lesions with multiple histological subtypes, each with distinct growth patterns, resulting in a spectrum of
tumor-specific prognoses;
pleomorphic adenoma (PA) and
mucoepidermoid carcinoma (MEC) are the most common representatives of these
neoplasms. Many studies have associated specific profiles of membrane and adhesion molecules in salivary gland tissues; these profiles appear to be relevant in
tumor biology as well as be interpreted as fingerprints for
tumor classification, diagnostic prognostic and therapeutic targets. One of these membrane molecule complexes are the tight junctions, composed by various
proteins, in which
claudins are protagonists. The aim of this study was to evaluate the expressions of genes that encode
tight junction proteins (CLDN-1, -3, -4, -5, -7, and -11,
occludin [OCLN], zonula occludens [TJP1, TJP2, and TJP3] and
junctional adhesion molecule A [F11R]) in MEC and PA using real time RT-PCR. We observed high expression of CLDN-1 and -7 and low expression of CLDN-3, -11 and TJP2 in MEC compared to PA. PA samples demonstrated high OCLN expression when compared to MEC. CRTC1::MAML2 fusion was detected in 12 of 20 (60.0%) MEC samples and was associated with CLDN7 expression, while the absence of fusion was associated with high histological grade. Increased CLDN5 expression was associated with submandibular gland
tumors. This study demonstrated differential expressions of genes encoding tight junction constituent
proteins and their associations with
tumor characteristics, suggesting their potential future role as diagnostic and prognostic markers.