GLYCOPROTEINS OF THE CARCINOEMBRYONIC ANTIGEN (CEA) FAMILY ARE EXPRESSED IN SWEAT AND SEBACEOUS GLANDS OF HUMAN FETAL AND ADULT SKIN

The carcinoembryonic antigen (CEA) family comprises a group of glycopr oteins including the classical CEA, nonspecific cross-reacting antigen s (NCA), and biliary glycoprotein (BGP). CEA glycoproteins have been i dentified in many glandular and mucosal tissues. In view of their puta tive role in cell adhesion, protein sorting, and signal transduction, CEA glycoproteins are thought to be involved in embryogenesis, archite ctual integrity, and secretory mechanisms of glandular epithelia. Sinc e there are few data available on the expression of CEA-like proteins in human skin, the aim of this study was to immunohistochemically spec ify and localize the CEA glycoproteins in cutaneous adult and fetal gl ands using a panel of well-characterized antibodies. The secretory par ts of eccrine sweat glands expressed CEA, NCA-90, and BGP, whereas apo crine glands remained unreactive for CEA glycoproteins. The ductal epi thelia of both eccrine and apocrine glands contained CEA and NCA-90. S ebaceous glands were stained for BGP only. Electron microscopy of swea t glands showed CEA glycoprotein expression in cytoplasmic organelles and on microvilli lining the ductal surface. In sebaceous glands, BGP were demonstrated in small vesicles and along the cell membranes of di fferentiating sebocytes. Fetal development of cutaneous glands was ass ociated with early expression of CEA glycoproteins. Additionally, mice transgenic for human CEA were shown to express CEA in sweat glands. T he overall distribution of CEA glycoproteins in cutaneous glands was c onsistent with that in epithelia of other glandular tissues.