MUCIN GENE-EXPRESSION IN HUMAN EMBRYONIC AND FETAL INTESTINE

Background-The intestinal epithelium is covered by a continuous layer of mucus which is secreted by well differentiated epithelial cells. Di sregulation of the expression of mucins has been reported to have poss ible implications in the neoplastic process which affects intestinal m ucosae. It is well known that preneoplastic and neoplastic tissues can express fetal phenotypic characteristics. Aims-To assess whether the expression of mucin genes in the intestinal tract is linked to the sta ge of cellular differentiation and tissue development, by studying the expression of six mucin genes in human fetal small intestine and colo n, and also adult tissues. Methods-In situ hybridisation was used to s tudy mRNA expression of MUC2, MUC3, MUC4, MUC5B, MUC5AC, and MUC6 in 3 2 human embryos and fetuses (6.5-27 weeks gestation). Normal adult muc osae were used as controls. Results-Three mucin genes, MUC2, MUC4, and MUC5AC, were differently expressed in fetal intestine compared with e xpression in normal adults. Conclusion-These differences in mucin gene expression suggest a possible regulatory role for these products in i ntestinal epithelial cell differentiation.