[Differential mucin expression in the gastrointestinal tract].

Under physiological conditions mucins display a tissue specific expression. MUC2, MUC3, MUC5AC and MUC6 are the major mucins in the gastrointestinal tract. In the intestinal tissue MUC2 and MUC3 are the predominant mucins, whereas MUC5AC and MUC6 are the most important mucins in the stomach. Pathophysiological conditions are characterized by an aberrant gene expression. This includes the expression of non-tissue specific mucins as well as a reduced expression of the specific mucins. During inflammation a co-expression of non-tissue specific mucins was observed. Neoplastic transformations are also associated with an aberrant mucin expression. Obviously, an increased expression of non-specific mucins is related with a more favorable prognosis, while a decreased mucin expression is indicative for an increased cellular dedifferentiation and a poor prognosis. This modified mucin expression may result from a modified gene expression as well as from modifications in the posttranscriptional processing. A modified mucin expression reflects pathophysiological conditions and may support the pathohistological diagnosis.