Immunohistochemical study of the association between the progression of pancreatic ductal lesions and the expression of MUC1, MUC2, MUC5AC, and E-cadherin.

Pancreatic cancer is a highly malignant tumor. In this study, we examined the association between the expression of MUC1, MUC2, MUC5AC, and E-cadherin, and the pathological changes from normal pancreatic tissue to invasive ductal carcinoma(IDC). Since MUC1 is known to be involved in the inhibition of E-cadherin, we also examined the association between MUC1 and E-cadherin. Five normal pancreatic tissues, 6 chronic pancreatitis tissues, 20 pancreatic intraepithelial neoplasia (PanIN) tissues, and 24 IDC tissues were fixed in formalin, embedded in paraffin, and sections were immunostained. MUC1 was positive in nonneoplastic tissues, PanIN-3, and IDC. MUC2 was negative in almost all tissues. MUC5AC was positive in neoplastic tissues. E-cadherin was positive in almost all tissues. Changes in MUC1 staining were observed in PanIN-3 and IDC, and E-cadherin staining was seen in neoplastic tissues. MUC1 was more diffusely positive in lymph node metastasis-positive cases. The expression of MUC1 and MUC5AC is associated with the progression of PanIN. MUC1 may promote the inhibition of E-cadherin. The results also suggest that MUC1 is useful as a prognostic marker.