MUC1 and MUC2 in pancreatic neoplasia

Abstract

MUCs are glycoproteins with various roles in homeostasis and carcinogenesis. Among other actions, MUC1 may inhibit cell-cell and cell-stroma interactions and function as a signal transducer, participating in cancer progression. In contrast, MUC2 is normally found only in goblet cells, where it contributes to the protective barrier function of these cells. Recently, a tumour suppressor role has been demonstrated for MUC2, and both MUC1 and MUC2 appear to have important roles in pancreatic neoplasia. MUC1 appears to be a marker of aggressive phenotype and may facilitate the vascular spread of carcinoma cells. In contrast, MUC2 is rarely detectable in aggressive pancreatic tumours, but is commonly expressed in intraductal papillary mucinous neoplasms (IPMNs), which are rare, indolent tumours, in intestinal IPMNs, and in indolent colloid carcinomas. MUC2 appears to be not only a marker of this indolent pathway, but also partly responsible for its less aggressive nature. Thus, in pancreatic neoplasia, MUC1 and MUC2 have potential diagnostic and prognostic value as markers of aggressive and indolent phenotypes, respectively, and have potential as therapeutic targets.

Figure 1

MUC1 and MUC2 staining of different entities. (A) MUC1 staining of an intraductal papillary mucinous neoplasm (IPMN), pancreatobiliary type; original magnification, ×100). (B) Lack of MUC2 staining of the same lesion; original magnification, ×100. (C) MUC1 staining of a grade 3 pancreatic intraepithelial neoplasia lesion; original magnification, ×100. (D) MUC2 staining of a villous intestinal-type IPMN; original magnification, ×200. (E) MUC1 staining of a ductal-type pancreatic adenocarcinoma; original magnification, ×100. (F) MUC2 staining of a colloid carcinoma of the pancreas; original magnification, ×100.