Characterization of tumor‑associated MUC1 and its glycans expressed in mucoepidermoid carcinoma

Abstract

Mucoepidermoid carcinoma (MEC) is one of the most frequently misdiagnosed tumors. Glycans are modulated by malignant transformation. Mucin 1 (MUC1) is a mucin whose expression is upregulated in various tumors, including MEC, and it has previously been investigated as a diagnostic and prognostic tumor marker. The present study aimed to reveal the differences in the mucin glycans between MEC and normal salivary glands (NSGs) to discover novel diagnostic markers. Soluble fractions of salivary gland homogenate prepared from three MEC salivary glands and 7 NSGs were evaluated. Mucins in MEC and NSGs were separated using supported molecular matrix electrophoresis, and stained with Alcian blue and monoclonal antibodies. The glycans of the separated mucins were analyzed by mass spectrometry. MUC1 was found in MEC but not in NSGs, and almost all glycans of MUC1 in MEC were sialylated, whereas the glycans of mucins in NSGs were less sialylated. The core 2 type glycans, (Hex) 2 (HexNAc) 2 (NeuAc) 1 and (Hex) 2 (HexNAc) 2 (NeuAc) 2 , were found to be significantly abundant glycans of MUC1 in MEC. MEC markedly produced MUC1 modified with sialylated core 2 glycans. These data were obtained from the soluble fractions of salivary gland homogenates. These findings provide a basis for the utilization of MUC1 as a serum diagnostic marker for the preoperative diagnosis of MEC.

Expression and localisation of MUC1 modified with sialylated core-2 O-glycans in mucoepidermoid carcinoma

“…1C). Mucins in all patients (1-3) with MEC and three patients (7,9,10) with NSGs were stained with AAL (Fig. 1D).…”

“…Previously, we found that MEC produced MUC1 distinctively modified by sialylated core-2 O -glycans (GlcNAcβ1-6(Galβ1-3)GalNAcαSer/Thr) 10 . However, it remains unclear which cells in MEC tissues produce such characteristic modified MUC1.…”

Expression of the membrane-associated mucin MUC-1 and its relationship with Ki67 in mucoepidermoid carcinoma of the salivary glands

“…Las investigaciones sobre la expresión de las mucinas, especialmente MUC-1, en distintos tipos de cánceres son numerosas 10 . Sin embargo, los trabajos sobre los tumores de las glándulas salivales son escasos, relacionados principalmente con el adenoma pleomórfico y el carcinoma mucoepidermoide 10,[12][13]17,[36][37] . La expresión de las mucinas unidas a membrana (MUC-1 y MUC-4) y las mucinas secretorias (MUC-2, MUC-5AC, MUC-5B, MUC-6, and MUC-7) fueron estudiadas en 40 carcinomas mucoepidermoides por Alos et al 12 .…”

Expression and localisation of MUC1 modified with sialylated core-2 O-glycans in mucoepidermoid carcinoma

“…Previously, we found that MEC produced MUC1 distinctively modi ed by sialylated core-2 O-glycans (GlcNAcβ1-6(Galβ1-3)GalNAcαSer/Thr) 10 . However, it remains unclear which cells in MEC tissues produce such characteristic modi ed MUC1.…”